Sadaf Fatima - Academia.edu (original) (raw)

Papers by Sadaf Fatima

Pakistan Journal of Medical and Health Sciences, Jul 30, 2022

Objective: Measure the EAT thickness by echocardiography in CAD patients and to compare it with h... more Objective: Measure the EAT thickness by echocardiography in CAD patients and to compare it with healthy adults of Karachi population. Study Design and setting: It is a case control study. The study was carried out in the radiology (Echocardiography)

Pakistan Journal of Medical and Health Sciences

Objective: Measure the EAT thickness by echocardiography in CAD patients and to compare it with h... more Objective: Measure the EAT thickness by echocardiography in CAD patients and to compare it with healthy adults of Karachi population. Study Design and setting: It is a case control study. The study was carried out in the radiology (Echocardiography) Department of Ziauddin University Hospital Clifton Campus, Karachi. Methodology: In this study, there were315 participants among them there were159 cases of coronary artery disease and 156 healthy adults. The participants were selected through non probability convenience sampling technique. After filling the proforma including basic information the echocardiography for EAT thickness calculation was done. The data was analyzed on SPSS version 20. Numerical variables were used to derive means and standard deviations while ANOVA was applied to determine the worth along with coronary artery disease and healthy groups. P- Value less than 0.05 was considered as significant. Results: EAT mean thickness was found to be 15.45 ± 7.16 mm. Coronary ...

International Journal of Biological Macromolecules, 2021

Protein aggregation is the major cause of several acute amyloid diseases such as Parkinson's, Hun... more Protein aggregation is the major cause of several acute amyloid diseases such as Parkinson's, Huntington's, Alzheimer's, Lysozyme Systemic amyloidosis, Diabetes-II etc. While these diseases have attracted much attention but the cure is still unavailable. In the present study, Human Serum Albumin (HSA) and Human Lysozyme (HL) were used as the model proteins to investigate their aggregations. Nanoclays are hydrous silicates found in clay fraction of soil and known as natural nanomaterials. They have long been used in several applications in healthrelated products. In the present paper, the different types of nanoclays (MMT K-10, MMT K-30, Halloysite, Bentonite) were used to inhibit the process of HSA and HL aggregation. Aggregation experiments were evaluated using several biophysical tools such as Turbidity measurements, Intrinsic fluorescence, 1-anilino-8naphthalene sulfonate (ANS), Thioflavin T (Th T), congo red (CR) binding assays and Circular dichroism. Results demonstrated that all the nanoclays inhibit the DTT-induced aggregation. However, bentonite and MMT K-10 were progressively intense and potent as they slowed down nucleation stage which can be perceived using several biophysical techniques. Hence, nanoclays can be used as an artificial chaperone and might provide effective treatment against several protein aggregation related disorders.

International Journal of Hydrogen Energy, 2021

Abstract Biodiesel and oxyhydrogen (HHO) gas have shown promising results in improving engine per... more Abstract Biodiesel and oxyhydrogen (HHO) gas have shown promising results in improving engine performance and emissions. In this work, the effects of HHO gas and 5% biodiesel blends (B5) and their combined use in a 315 cc diesel engine have been analyzed. Biodiesel is produced by base catalyzed transesterification and cleaned by emulsification. Its calculated cetane index (CCI) was 61.4. HHO gas is produced from electrolysis of concentrated potassium hydroxide solution. The use of 5% biodiesel blend resulted in a significant rise of 9.4% in the brake thermal efficiency (BTE) and a maximum reduction of 8.19% in the brake specific fuel consumption (BSFC). HHO enrichment of diesel and biodiesel at 2.81 L/min through the intake manifold improved the torque and power by an average of over 3%. HHO addition also improved the BTE of diesel by a maximum of 3.67%. The combination of high CCI biodiesel fuel and HHO creates a mixture that has shortened the ignition delay (ID) to the point that adverse effects were observed due to the premature combustion as shown by the average decrease in the BTE of 2.97% compared to B5. Thus, B5, on its own, is found to be the optimum fuel under these conditions.

Current Enzyme Inhibition, 2018

Background: Trypsin Inhibitors are one of the most promising and investigated subject for their r... more Background: Trypsin Inhibitors are one of the most promising and investigated subject for their role in pharmacognostical and pharmacological studies. The paper describes purification and characterization of trypsin inhibitor obtained from blackeyed cowpea (Vigna unguiculata). The purification procedure of Vigna unguiculata trypsin inhibitor (VUTI) includes homogenization followed by ammonium sulphate precipitation. The protein thus precipitated was further dialysed and purified by ion exchange chromatography and gel permeation chromatography. The molecular weight was determined by SDS-PAGE. The protein thus purified was characterized biochemically to demonstrate curative potential as strong antioxidant, anti-inflammatory and antimicrobial agent. The 15 kDa VUTI obtained showed IC 50 values 490 g/ml compared to standard which was 254 g/ml in 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay. Also, the highest ferric reducing antioxidant power (FRAP) results confirmed the highest FRAP value of 0.405 mM at 1000 μg/ml and the lowest value of 0.113 mM at 100 μg/ml which were quite comparable to ascorbic acid (standard). Anti-inflammatory activity of VUTI was depicted by the method of inhibition of albumin denaturation where, VUTI showed high IC 50 value of 696.46 g/ml. Also, VUTI showed good antibacterial potential by inhibiting all tested bacterial strains with maximum inhibition against Bacillus subtilis (99.62%) and minimum against Staphylococcus aureus (34.62%). The results were quite comparable with standard drug ampicillin (5 mg/ml). Unfortunately, VUTI failed to show any activity against fungi. Thus, the results obtained depict that VUTI additionally be a wonderful candidate for development of novel antibacterial drugs, and it can also be used to reduce the deletorious effects of free radicals.

Biotechnology reports (Amsterdam, Netherlands), 2018

Triphala, an Indian ayurvedic triherbal formulation, is an equiproportional mixture of fruits of ... more Triphala, an Indian ayurvedic triherbal formulation, is an equiproportional mixture of fruits of three herbs, (), () and (). The present study focused on phytocompounds detection and comparative analysis of various biochemical activities in the aqueous and methanolic extracts of triphala and its constituting herbs. Antioxidant activity was determined by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), super oxide dismutase (SOD), catalase assay. Antibacterial potential was determined by broth dilution and agar well diffusion assays. Results revealed the presence of valuable bioactive compounds such as flavonoids, alkaloids, phenols, etc which might be responsible for biochemical activities. Extracts exhibited satisfactory radical-scavenging activity comparable with ascorbic acid. Methanolic extracts demonstrated higher antioxidant activity compared to aqueous extract. Extracts showed promising antibacterial potential against tested strain comparable t...

Journal of dietary supplements, Jan 18, 2018

Protease inhibitors are one of the most promising and investigated subjects for their role in pha... more Protease inhibitors are one of the most promising and investigated subjects for their role in pharmacognostic and pharmacological studies. This study aimed to investigate antioxidant, anti-inflammatory, and antimicrobial activities of trypsin inhibitors (TIs) from two plant sources (Cajanus cajan and Phaseolus limensis). TI was purified from C. cajan (PUSA-992) by ammonium sulfate precipitation followed by ion exchange chromatography. TI from Phaseolus limensis (lima bean trypsin inhibitor; LBTI) was procured from Sigma-Aldrich, St. Louis, Missouri, United States. The antioxidant activity was analyzed by ferric ion reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH). The anti-inflammatory property of TIs was determined by inhibition of albumin denaturation assay. Ascorbic acid and aspirin were used as standards for antioxidant and anti-inflammatory assays, respectively. These TIs were tested against various bacterial and fungal strains. The TIs showed DPPH rad...

International Journal of Biological Macromolecules, 2017

In this study, we have analyzed the structural and functional changes in the nature of Allium sat... more In this study, we have analyzed the structural and functional changes in the nature of Allium sativum Protease Inhibitor (ASPI) on undergoing various denaturation with variable range of pH, temperature and urea (at pH 8.2). ASPI being anti-tryptic in nature has native molecular mass of ∼15 kDa. The conformational stability, functional parameters and their correlation were estimated under different conditions using circular dichroism, fluorescence and activity measurements. ASPI was found to fall in belongs to ␣+␤ protein. It demonstrated structural and functional stability in the pH range 5.0-12.0 and up to70 • C temperature. Further decrease in pH and increase in temperature induces unfolding followed by aggregation. Chemical induced denaturation was found to be cooperative and transitions were reversible and sigmoid. T m (midpoint of denaturation), C p (constant pressure heat capacity change) and H m (van't Hoff enthalpy change at T m were calculated to be 41.25 ± 0.2 • C, 1.3 ± 0.07 kcal mol -1 K -1 and 61 ± 2 kcal mol -1 respectively for thermally denatured ASPI earlier. The reversibility of the protein was confirmed for both thermally and chemically denatured ASPI. The results obtained from trypsin inhibitory activity assay and structural studies are found to be in a significant correlation and hence established structure-function relationship of ASPI.

Clinica chimica acta; international journal of clinical chemistry, 2017

Sodium fluorescein (SF) is a fluorescent tracer dye used extensively in diagnostic tools in the f... more Sodium fluorescein (SF) is a fluorescent tracer dye used extensively in diagnostic tools in the field of Ophthalmology, particularly in intravenous fluorescein angiography (IVFA). The binding of SF to human serum albumin (HSA) has been predicted by molecular docking and investigated by circular dichroism (CD) and fluorescence spectroscopy with or without glycation at temperatures 296, 301, and 310K. The binding parameters were calculated by quenching of emission spectrum of a constant concentration of SF (2μmol/l) at 513nm against increasing concentrations of glycated or unmodified HSA as quencher starting from stoichiometry ratio of 1:1. The HSA-SF interaction found to be a static binding. The Stern-Volmer constants (Ksv) were in the range of ~10(4)M(-1) and other thermodynamic parameters like enthalpy (ΔH°), free energy (ΔG°) and entropy (ΔS°) are similar to albumin ligand bindings reported by previous workers. The interactions were found to be spontaneous, irrespective of tempera...

PloS one, 2017

A novel extracellular laccase enzyme produced from Spirulina platensis CFTRI was purified by ultr... more A novel extracellular laccase enzyme produced from Spirulina platensis CFTRI was purified by ultrafiltration, cold acetone precipitation, anion exchange and size exclusion chromatography with 51.5% recovery and 5.8 purification fold. The purified laccase was a monomeric protein with molecular mass of ~66 kDa that was confirmed by zymogram analysis and peptide mass fingerprinting. The optimum pH and temperature of the enzyme activity was found at 3.0 and 30°C using ABTS as substrate but the enzyme was quite stable at high temperature and alkaline pH. The laccase activity was enhanced by Cu+2, Zn+2 and Mn+2. In addition, the dye decolorization potential of purified laccase was much higher in terms of extent as well as time. The purified laccase decolorized (96%) of anthraquinonic dye Reactive blue- 4 within 4 h and its biodegradation studies was monitored by UV visible spectra, FTIR and HPLC which concluded that cyanobacterial laccase can be efficiently used to decolorize synthetic dy...

International Journal of Biological Macromolecules, 2017

This review helps to understand protein misfolding events, which results in protein aggregation, ... more This review helps to understand protein misfolding events, which results in protein aggregation, and hence to related neurodegenerative diseases. Many chaperones and folding factors are found inside the cell system for the proper folding of protein. If protein gets misfolded, it may accumulate in cells and can lead to several fatal diseases. In some cases, misfolded proteins aggregated in form of loop-sheet polymer and amyloid fibril when they escape the degradation process and leads to neurodegenerative disorders. Nanoparticles (NPs) are nano-sized materials, can be formulated by using organic molecules such as gelatin, chitosan, inorganic molecules, metals such as iron, gold, silver, etc. NPs unite with proteins and form a dynamic nanoparticle-protein (NP-P) corona. Conformational changes may be induced in adsorbed protein by this NP-P corona which might change overall bio-reactivity of NP. They can influence correct folding of unfolded or misfolded protein and prevent their aggregation which may be helpful in the cure of neurodegenerative disorders. Due to high area:size ratio, NPs have higher advantages over bulk materials. Hence, the effect of NPs on the proper protein folding opens new gateways to produce a biologically active three dimensional biomolecule.

Open Pharmaceutical Sciences Journal, 2016

Background:Proteases are important enzymes that can degrade proteins and are found in animals, pl... more Background:Proteases are important enzymes that can degrade proteins and are found in animals, plants, bacteria, fungi and viruses. The action of proteases can be controlled by Protease Inhibitors (PIs), chemical or proteinaceous in nature that can block the active site of protease. Since the step catalyzed by proteases may play important role in life cycle of microbes, hindering the action of proteases by PIs may act as therapeutic intervention for microbial infection.Material and Methods:A thorough study was performed and wide range of literature was surveyed to confirm our results of PIs showing antibacterial activity.Results:PIs have shown to be effective drugs against bacterial pathogens, pathogenic viruses- Human Immunodeficiency Virus (HIV), Herpes virus, Hepatitis Virus. PIs have recently been investigated for controlling protozoan parasites. Clinical value of proteases and their inhibitors has been studied inHelicobacter pyloriwhich is the etiologic agent of gastritis.Concl...

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2009

The interaction of thioflavin T (ThT) with serum albumins from four different mammalian species i... more The interaction of thioflavin T (ThT) with serum albumins from four different mammalian species i.e. human, bovine, porcine and rabbit, has been investigated by circular dichroism (CD), fluorescence spectroscopy and ITC. The binding constant (K) for HSA was found to be 9.9 × 10 4 M -1 , 4.3 × 10 4 M -1 for RSA, 1.07 × 10 4 M -1 for PSA and 0.3 × 10 4 M -1 for BSA and the number of binding sites (n) were 1.14, 1.06, 0.94 and 0.8, respectively, which is very significant. By using unfolding pathway of HSA in the presence of urea, domain II of HSA has been assigned to possess binding site of ThT. Its binding constant is comparable to many drugs that bind at domain II of HSA, like salicylate, warfarin, digitoxin, etc. Acting force between HSA and ThT is showing that both hydrophobic and electrostatic forces have contributed for the interaction. G binding , H and S were calculated to be -28.46 kJ mol -1 , -3.50 kJ mol -1 and 81.04 J K -1 mol -1 , respectively. The data described here will help to increase our understanding about the interaction of ThT with native proteins. The results also indicate that care must be taken while using ThT as a probe for detecting amyloid fibrils.

Protein & Peptide Letters, 2009

Protein & Peptide Letters, 2008

We have previously characterized an acid-unfolded (U A ) state of Mucor miehei lipase at pH 2. Th... more We have previously characterized an acid-unfolded (U A ) state of Mucor miehei lipase at pH 2. The effect of 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) resulted in characterization of molten-globule (MG) like states with -sheet secondary structure at 15% (v/v) TFE and 6% (v/v) HFIP. -Helical states accumulate at 80% (v/v) TFE and 30% (v/v) HFIP.

IUBMB Life, 2007

Studies on the acid-induced denaturation of Mucor miehei lipase (E.C. 3.1.1.3) were performed by ... more Studies on the acid-induced denaturation of Mucor miehei lipase (E.C. 3.1.1.3) were performed by circular dichroism (CD) spectroscopy, fluorescence emission spectroscopy and binding of hydrophobic dye, 1-anilino 8-naphthalenesulfonic acid (ANS). Acid denaturation of the lipase showed loss of secondary structure and alterations in the tertiary structure in the pH range 4 to 2 and 7 to 2 respectively, suggesting that the lipase exists as an acid-unfolded state *pH 2.0. A further decrease in pH (from 2.0 to 1.0) resulted in a second transition, which corresponded to the formation of both secondary and tertiary structures. The acid unfolded state at around pH 2.0 has been characterized by significant loss of secondary structure and a small increase in fluorescence intensity with a blue shift of 2 nm, indicating shift of tryptophan residues to less polar environment. Interestingly, the lipase at pH 1.0 exhibits characteristics of molten globule, such as enhanced binding of hydrophobic dye (ANS), native-like secondary structure and slightly altered tryptophanyl environments. That the molten globule of the lipase at pH 1.0 also possesses native-like tertiary structure is an interesting observation made for this lipase.

International Journal of Biological Macromolecules, 2009

Biochimie, 2010

Wheat germ lipase is a cereal lipase which is a monomeric protein. In the present study we sought... more Wheat germ lipase is a cereal lipase which is a monomeric protein. In the present study we sought to structurally characterize this protein along with equilibrium unfolding in solution. Conformational changes occurring in the protein with varying pH, were monitored by circular dichroism (CD) spectroscopy, fluorescence emission spectroscopy, binding of hydrophobic dye, 1-anilino 8-naphthalenesulfonic acid (ANS) and dynamic light scattering (DLS). Our study showed that acid denaturation of lipase lead to characterization of multiple monomeric intermediates. Native protein at pH 7.0 showed far-UV spectrum indicating mixed structure with both alpha and beta-type of characteristics. Activity of lipase was found to fall on either sides of pH 7.0e8.0. Acid-unfolded state was characterized at pH 4.0 with residual secondary structure, disrupted tertiary spectrum and red-shifted fluorescence spectrum with decreased intensity. Further decrease in pH lead to formation of secondary structure and acidinduced molten globule state was found to be stabilized at pH 1.4, with exposed tryptophan residues and hydrophobic patches. Notably, interesting finding of this study was characterization of acid-induced state at pH 0.8 with higher secondary structure content than native lipase, regain in tertiary spectrum and induction of compact conformation. Although enzymatically inactive, acid-induced state at pH 0.8 was found to be structurally more stable than native lipase, as shown by chemical and thermal denaturation profiles.

Archives of Biochemistry and Biophysics, 2004

A systematic investigation of the effects of aqueous 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) and... more A systematic investigation of the effects of aqueous 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) and 2,2,2-trifluoroethanol (TFE) on the structure of acid-unfolded papain (EC. 3.4.22.2) was made using circular dichroism (CD), intrinsic tryptophan fluorescence, and 1-anilino 8-sulfonic acid (ANS) binding. At pH 2, papain exhibits substantial secondary structure as beta-sheet and is relatively less denatured as compared to 6 M guanidine hydrochloride (GdnHCl) but loses the persistent tertiary structure of the native state. Addition of HFIP and TFE caused an induction of alpha-helical structure as evident from the increase in the mean residue ellipticity value at 208 and 222 nm. Induction was 20% more in HFIP than TFE. Interestingly, at 13% (v/v) HFIP and 30% (v/v) TFE a near-UV CD spectrum approaches the native-like spectral features. Tryptophan fluorescence studies indicate the change in the environment of the tryptophan residues on the addition of HFIP and TFE to acid-unfolded papain. Maximum ANS binding occurs at 13% (v/v) HFIP and 30% (v/v) TFE, suggesting a compact "molten globule"-like conformation with enhanced exposure of hydrophobic surface area. Acid-unfolded papain in presence of 13% (v/v) HFIP and 30% (v/v) TFE showed the recovery of enzymatic activity by 54 and 61%, respectively. Thermal stability of these states was assessed by changes in fluorescence emission maximum and absorbance at 292 nm. Temperature-induced unfolding of papain at pH 2 was non-cooperative and the transition curves were biphasic in nature. Temperature-induced unfolding of HFIP and TFE-induced state was weakly cooperative in comparison to cooperative transition of native.

Archives of Biochemistry and Biophysics, 2006

Concanavalin A (Con A) exists in dimeric state at pH 5. In concentration range 20-60% (v/v) 2,2,2... more Concanavalin A (Con A) exists in dimeric state at pH 5. In concentration range 20-60% (v/v) 2,2,2-trifluoroethanol (TFE) and 2-40% (v/v) 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), Con A at pH 5.0 shows visible aggregation. However, when succinyl Con A was used, no aggregation was observed in the entire concentration range of fluoroalcohols (0-90% v/v TFE and HFIP) and resulted in stable a-helix formation. Temperature-induced concentration-dependent aggregation in Con A was also found to be prevented/reduced in succinylated form. Possible role of electrostatic repulsion among residues in the prevention of hydrophobically driven aggregation has been discussed. Results indicate that succinylation of a protein resulted in greater stability (in both b-sheet and a-helical forms) against alcohol-induced and temperature-induced concentration-dependent aggregation and this observation may play significant role in amyloid-forming proteins. Effect of TFE and HFIP on the conformation of a dimeric protein, Succinylated Con A, has been investigated by circular dichroism (CD), fluorescence emission spectroscopy, binding of hydrophobic dye ANS (8-anilinonaphthalene-1-sulfonic acid). Far UV-CD, a probe for secondary structure shows loss of native secondary structure in the presence of low concentration of both the alcohols, TFE (10% v/v) and HFIP (4% v/v). Upon addition of higher concentration of these alcohols, Succinylated Con A exhibited transformation from b-sheet to a-helical structure. Intrinsic tryptophan fluorescence studies, ANS binding and near UV-CD experiments indicate the protein is more expanded, have more exposed hydrophobic surfaces and highly disrupted tertiary structure at 60% (v/v) TFE and 30% (v/v) HFIP concentrations. Taken together, these results it might be concluded that TFE and HFIP induce two intermediate states at their low and high concentrations in Succinyl Con A.

Pakistan Journal of Medical and Health Sciences, Jul 30, 2022

Objective: Measure the EAT thickness by echocardiography in CAD patients and to compare it with h... more Objective: Measure the EAT thickness by echocardiography in CAD patients and to compare it with healthy adults of Karachi population. Study Design and setting: It is a case control study. The study was carried out in the radiology (Echocardiography)

Pakistan Journal of Medical and Health Sciences

Objective: Measure the EAT thickness by echocardiography in CAD patients and to compare it with h... more Objective: Measure the EAT thickness by echocardiography in CAD patients and to compare it with healthy adults of Karachi population. Study Design and setting: It is a case control study. The study was carried out in the radiology (Echocardiography) Department of Ziauddin University Hospital Clifton Campus, Karachi. Methodology: In this study, there were315 participants among them there were159 cases of coronary artery disease and 156 healthy adults. The participants were selected through non probability convenience sampling technique. After filling the proforma including basic information the echocardiography for EAT thickness calculation was done. The data was analyzed on SPSS version 20. Numerical variables were used to derive means and standard deviations while ANOVA was applied to determine the worth along with coronary artery disease and healthy groups. P- Value less than 0.05 was considered as significant. Results: EAT mean thickness was found to be 15.45 ± 7.16 mm. Coronary ...

International Journal of Biological Macromolecules, 2021

Protein aggregation is the major cause of several acute amyloid diseases such as Parkinson's, Hun... more Protein aggregation is the major cause of several acute amyloid diseases such as Parkinson's, Huntington's, Alzheimer's, Lysozyme Systemic amyloidosis, Diabetes-II etc. While these diseases have attracted much attention but the cure is still unavailable. In the present study, Human Serum Albumin (HSA) and Human Lysozyme (HL) were used as the model proteins to investigate their aggregations. Nanoclays are hydrous silicates found in clay fraction of soil and known as natural nanomaterials. They have long been used in several applications in healthrelated products. In the present paper, the different types of nanoclays (MMT K-10, MMT K-30, Halloysite, Bentonite) were used to inhibit the process of HSA and HL aggregation. Aggregation experiments were evaluated using several biophysical tools such as Turbidity measurements, Intrinsic fluorescence, 1-anilino-8naphthalene sulfonate (ANS), Thioflavin T (Th T), congo red (CR) binding assays and Circular dichroism. Results demonstrated that all the nanoclays inhibit the DTT-induced aggregation. However, bentonite and MMT K-10 were progressively intense and potent as they slowed down nucleation stage which can be perceived using several biophysical techniques. Hence, nanoclays can be used as an artificial chaperone and might provide effective treatment against several protein aggregation related disorders.

International Journal of Hydrogen Energy, 2021

Abstract Biodiesel and oxyhydrogen (HHO) gas have shown promising results in improving engine per... more Abstract Biodiesel and oxyhydrogen (HHO) gas have shown promising results in improving engine performance and emissions. In this work, the effects of HHO gas and 5% biodiesel blends (B5) and their combined use in a 315 cc diesel engine have been analyzed. Biodiesel is produced by base catalyzed transesterification and cleaned by emulsification. Its calculated cetane index (CCI) was 61.4. HHO gas is produced from electrolysis of concentrated potassium hydroxide solution. The use of 5% biodiesel blend resulted in a significant rise of 9.4% in the brake thermal efficiency (BTE) and a maximum reduction of 8.19% in the brake specific fuel consumption (BSFC). HHO enrichment of diesel and biodiesel at 2.81 L/min through the intake manifold improved the torque and power by an average of over 3%. HHO addition also improved the BTE of diesel by a maximum of 3.67%. The combination of high CCI biodiesel fuel and HHO creates a mixture that has shortened the ignition delay (ID) to the point that adverse effects were observed due to the premature combustion as shown by the average decrease in the BTE of 2.97% compared to B5. Thus, B5, on its own, is found to be the optimum fuel under these conditions.

Current Enzyme Inhibition, 2018

Background: Trypsin Inhibitors are one of the most promising and investigated subject for their r... more Background: Trypsin Inhibitors are one of the most promising and investigated subject for their role in pharmacognostical and pharmacological studies. The paper describes purification and characterization of trypsin inhibitor obtained from blackeyed cowpea (Vigna unguiculata). The purification procedure of Vigna unguiculata trypsin inhibitor (VUTI) includes homogenization followed by ammonium sulphate precipitation. The protein thus precipitated was further dialysed and purified by ion exchange chromatography and gel permeation chromatography. The molecular weight was determined by SDS-PAGE. The protein thus purified was characterized biochemically to demonstrate curative potential as strong antioxidant, anti-inflammatory and antimicrobial agent. The 15 kDa VUTI obtained showed IC 50 values 490 g/ml compared to standard which was 254 g/ml in 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay. Also, the highest ferric reducing antioxidant power (FRAP) results confirmed the highest FRAP value of 0.405 mM at 1000 μg/ml and the lowest value of 0.113 mM at 100 μg/ml which were quite comparable to ascorbic acid (standard). Anti-inflammatory activity of VUTI was depicted by the method of inhibition of albumin denaturation where, VUTI showed high IC 50 value of 696.46 g/ml. Also, VUTI showed good antibacterial potential by inhibiting all tested bacterial strains with maximum inhibition against Bacillus subtilis (99.62%) and minimum against Staphylococcus aureus (34.62%). The results were quite comparable with standard drug ampicillin (5 mg/ml). Unfortunately, VUTI failed to show any activity against fungi. Thus, the results obtained depict that VUTI additionally be a wonderful candidate for development of novel antibacterial drugs, and it can also be used to reduce the deletorious effects of free radicals.

Biotechnology reports (Amsterdam, Netherlands), 2018

Triphala, an Indian ayurvedic triherbal formulation, is an equiproportional mixture of fruits of ... more Triphala, an Indian ayurvedic triherbal formulation, is an equiproportional mixture of fruits of three herbs, (), () and (). The present study focused on phytocompounds detection and comparative analysis of various biochemical activities in the aqueous and methanolic extracts of triphala and its constituting herbs. Antioxidant activity was determined by 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), super oxide dismutase (SOD), catalase assay. Antibacterial potential was determined by broth dilution and agar well diffusion assays. Results revealed the presence of valuable bioactive compounds such as flavonoids, alkaloids, phenols, etc which might be responsible for biochemical activities. Extracts exhibited satisfactory radical-scavenging activity comparable with ascorbic acid. Methanolic extracts demonstrated higher antioxidant activity compared to aqueous extract. Extracts showed promising antibacterial potential against tested strain comparable t...

Journal of dietary supplements, Jan 18, 2018

Protease inhibitors are one of the most promising and investigated subjects for their role in pha... more Protease inhibitors are one of the most promising and investigated subjects for their role in pharmacognostic and pharmacological studies. This study aimed to investigate antioxidant, anti-inflammatory, and antimicrobial activities of trypsin inhibitors (TIs) from two plant sources (Cajanus cajan and Phaseolus limensis). TI was purified from C. cajan (PUSA-992) by ammonium sulfate precipitation followed by ion exchange chromatography. TI from Phaseolus limensis (lima bean trypsin inhibitor; LBTI) was procured from Sigma-Aldrich, St. Louis, Missouri, United States. The antioxidant activity was analyzed by ferric ion reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH). The anti-inflammatory property of TIs was determined by inhibition of albumin denaturation assay. Ascorbic acid and aspirin were used as standards for antioxidant and anti-inflammatory assays, respectively. These TIs were tested against various bacterial and fungal strains. The TIs showed DPPH rad...

International Journal of Biological Macromolecules, 2017

In this study, we have analyzed the structural and functional changes in the nature of Allium sat... more In this study, we have analyzed the structural and functional changes in the nature of Allium sativum Protease Inhibitor (ASPI) on undergoing various denaturation with variable range of pH, temperature and urea (at pH 8.2). ASPI being anti-tryptic in nature has native molecular mass of ∼15 kDa. The conformational stability, functional parameters and their correlation were estimated under different conditions using circular dichroism, fluorescence and activity measurements. ASPI was found to fall in belongs to ␣+␤ protein. It demonstrated structural and functional stability in the pH range 5.0-12.0 and up to70 • C temperature. Further decrease in pH and increase in temperature induces unfolding followed by aggregation. Chemical induced denaturation was found to be cooperative and transitions were reversible and sigmoid. T m (midpoint of denaturation), C p (constant pressure heat capacity change) and H m (van't Hoff enthalpy change at T m were calculated to be 41.25 ± 0.2 • C, 1.3 ± 0.07 kcal mol -1 K -1 and 61 ± 2 kcal mol -1 respectively for thermally denatured ASPI earlier. The reversibility of the protein was confirmed for both thermally and chemically denatured ASPI. The results obtained from trypsin inhibitory activity assay and structural studies are found to be in a significant correlation and hence established structure-function relationship of ASPI.

Clinica chimica acta; international journal of clinical chemistry, 2017

Sodium fluorescein (SF) is a fluorescent tracer dye used extensively in diagnostic tools in the f... more Sodium fluorescein (SF) is a fluorescent tracer dye used extensively in diagnostic tools in the field of Ophthalmology, particularly in intravenous fluorescein angiography (IVFA). The binding of SF to human serum albumin (HSA) has been predicted by molecular docking and investigated by circular dichroism (CD) and fluorescence spectroscopy with or without glycation at temperatures 296, 301, and 310K. The binding parameters were calculated by quenching of emission spectrum of a constant concentration of SF (2μmol/l) at 513nm against increasing concentrations of glycated or unmodified HSA as quencher starting from stoichiometry ratio of 1:1. The HSA-SF interaction found to be a static binding. The Stern-Volmer constants (Ksv) were in the range of ~10(4)M(-1) and other thermodynamic parameters like enthalpy (ΔH°), free energy (ΔG°) and entropy (ΔS°) are similar to albumin ligand bindings reported by previous workers. The interactions were found to be spontaneous, irrespective of tempera...

PloS one, 2017

A novel extracellular laccase enzyme produced from Spirulina platensis CFTRI was purified by ultr... more A novel extracellular laccase enzyme produced from Spirulina platensis CFTRI was purified by ultrafiltration, cold acetone precipitation, anion exchange and size exclusion chromatography with 51.5% recovery and 5.8 purification fold. The purified laccase was a monomeric protein with molecular mass of ~66 kDa that was confirmed by zymogram analysis and peptide mass fingerprinting. The optimum pH and temperature of the enzyme activity was found at 3.0 and 30°C using ABTS as substrate but the enzyme was quite stable at high temperature and alkaline pH. The laccase activity was enhanced by Cu+2, Zn+2 and Mn+2. In addition, the dye decolorization potential of purified laccase was much higher in terms of extent as well as time. The purified laccase decolorized (96%) of anthraquinonic dye Reactive blue- 4 within 4 h and its biodegradation studies was monitored by UV visible spectra, FTIR and HPLC which concluded that cyanobacterial laccase can be efficiently used to decolorize synthetic dy...

International Journal of Biological Macromolecules, 2017

This review helps to understand protein misfolding events, which results in protein aggregation, ... more This review helps to understand protein misfolding events, which results in protein aggregation, and hence to related neurodegenerative diseases. Many chaperones and folding factors are found inside the cell system for the proper folding of protein. If protein gets misfolded, it may accumulate in cells and can lead to several fatal diseases. In some cases, misfolded proteins aggregated in form of loop-sheet polymer and amyloid fibril when they escape the degradation process and leads to neurodegenerative disorders. Nanoparticles (NPs) are nano-sized materials, can be formulated by using organic molecules such as gelatin, chitosan, inorganic molecules, metals such as iron, gold, silver, etc. NPs unite with proteins and form a dynamic nanoparticle-protein (NP-P) corona. Conformational changes may be induced in adsorbed protein by this NP-P corona which might change overall bio-reactivity of NP. They can influence correct folding of unfolded or misfolded protein and prevent their aggregation which may be helpful in the cure of neurodegenerative disorders. Due to high area:size ratio, NPs have higher advantages over bulk materials. Hence, the effect of NPs on the proper protein folding opens new gateways to produce a biologically active three dimensional biomolecule.

Open Pharmaceutical Sciences Journal, 2016

Background:Proteases are important enzymes that can degrade proteins and are found in animals, pl... more Background:Proteases are important enzymes that can degrade proteins and are found in animals, plants, bacteria, fungi and viruses. The action of proteases can be controlled by Protease Inhibitors (PIs), chemical or proteinaceous in nature that can block the active site of protease. Since the step catalyzed by proteases may play important role in life cycle of microbes, hindering the action of proteases by PIs may act as therapeutic intervention for microbial infection.Material and Methods:A thorough study was performed and wide range of literature was surveyed to confirm our results of PIs showing antibacterial activity.Results:PIs have shown to be effective drugs against bacterial pathogens, pathogenic viruses- Human Immunodeficiency Virus (HIV), Herpes virus, Hepatitis Virus. PIs have recently been investigated for controlling protozoan parasites. Clinical value of proteases and their inhibitors has been studied inHelicobacter pyloriwhich is the etiologic agent of gastritis.Concl...

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2009

The interaction of thioflavin T (ThT) with serum albumins from four different mammalian species i... more The interaction of thioflavin T (ThT) with serum albumins from four different mammalian species i.e. human, bovine, porcine and rabbit, has been investigated by circular dichroism (CD), fluorescence spectroscopy and ITC. The binding constant (K) for HSA was found to be 9.9 × 10 4 M -1 , 4.3 × 10 4 M -1 for RSA, 1.07 × 10 4 M -1 for PSA and 0.3 × 10 4 M -1 for BSA and the number of binding sites (n) were 1.14, 1.06, 0.94 and 0.8, respectively, which is very significant. By using unfolding pathway of HSA in the presence of urea, domain II of HSA has been assigned to possess binding site of ThT. Its binding constant is comparable to many drugs that bind at domain II of HSA, like salicylate, warfarin, digitoxin, etc. Acting force between HSA and ThT is showing that both hydrophobic and electrostatic forces have contributed for the interaction. G binding , H and S were calculated to be -28.46 kJ mol -1 , -3.50 kJ mol -1 and 81.04 J K -1 mol -1 , respectively. The data described here will help to increase our understanding about the interaction of ThT with native proteins. The results also indicate that care must be taken while using ThT as a probe for detecting amyloid fibrils.

Protein & Peptide Letters, 2009

Protein & Peptide Letters, 2008

We have previously characterized an acid-unfolded (U A ) state of Mucor miehei lipase at pH 2. Th... more We have previously characterized an acid-unfolded (U A ) state of Mucor miehei lipase at pH 2. The effect of 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) resulted in characterization of molten-globule (MG) like states with -sheet secondary structure at 15% (v/v) TFE and 6% (v/v) HFIP. -Helical states accumulate at 80% (v/v) TFE and 30% (v/v) HFIP.

IUBMB Life, 2007

Studies on the acid-induced denaturation of Mucor miehei lipase (E.C. 3.1.1.3) were performed by ... more Studies on the acid-induced denaturation of Mucor miehei lipase (E.C. 3.1.1.3) were performed by circular dichroism (CD) spectroscopy, fluorescence emission spectroscopy and binding of hydrophobic dye, 1-anilino 8-naphthalenesulfonic acid (ANS). Acid denaturation of the lipase showed loss of secondary structure and alterations in the tertiary structure in the pH range 4 to 2 and 7 to 2 respectively, suggesting that the lipase exists as an acid-unfolded state *pH 2.0. A further decrease in pH (from 2.0 to 1.0) resulted in a second transition, which corresponded to the formation of both secondary and tertiary structures. The acid unfolded state at around pH 2.0 has been characterized by significant loss of secondary structure and a small increase in fluorescence intensity with a blue shift of 2 nm, indicating shift of tryptophan residues to less polar environment. Interestingly, the lipase at pH 1.0 exhibits characteristics of molten globule, such as enhanced binding of hydrophobic dye (ANS), native-like secondary structure and slightly altered tryptophanyl environments. That the molten globule of the lipase at pH 1.0 also possesses native-like tertiary structure is an interesting observation made for this lipase.

International Journal of Biological Macromolecules, 2009

Biochimie, 2010

Wheat germ lipase is a cereal lipase which is a monomeric protein. In the present study we sought... more Wheat germ lipase is a cereal lipase which is a monomeric protein. In the present study we sought to structurally characterize this protein along with equilibrium unfolding in solution. Conformational changes occurring in the protein with varying pH, were monitored by circular dichroism (CD) spectroscopy, fluorescence emission spectroscopy, binding of hydrophobic dye, 1-anilino 8-naphthalenesulfonic acid (ANS) and dynamic light scattering (DLS). Our study showed that acid denaturation of lipase lead to characterization of multiple monomeric intermediates. Native protein at pH 7.0 showed far-UV spectrum indicating mixed structure with both alpha and beta-type of characteristics. Activity of lipase was found to fall on either sides of pH 7.0e8.0. Acid-unfolded state was characterized at pH 4.0 with residual secondary structure, disrupted tertiary spectrum and red-shifted fluorescence spectrum with decreased intensity. Further decrease in pH lead to formation of secondary structure and acidinduced molten globule state was found to be stabilized at pH 1.4, with exposed tryptophan residues and hydrophobic patches. Notably, interesting finding of this study was characterization of acid-induced state at pH 0.8 with higher secondary structure content than native lipase, regain in tertiary spectrum and induction of compact conformation. Although enzymatically inactive, acid-induced state at pH 0.8 was found to be structurally more stable than native lipase, as shown by chemical and thermal denaturation profiles.

Archives of Biochemistry and Biophysics, 2004

A systematic investigation of the effects of aqueous 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) and... more A systematic investigation of the effects of aqueous 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) and 2,2,2-trifluoroethanol (TFE) on the structure of acid-unfolded papain (EC. 3.4.22.2) was made using circular dichroism (CD), intrinsic tryptophan fluorescence, and 1-anilino 8-sulfonic acid (ANS) binding. At pH 2, papain exhibits substantial secondary structure as beta-sheet and is relatively less denatured as compared to 6 M guanidine hydrochloride (GdnHCl) but loses the persistent tertiary structure of the native state. Addition of HFIP and TFE caused an induction of alpha-helical structure as evident from the increase in the mean residue ellipticity value at 208 and 222 nm. Induction was 20% more in HFIP than TFE. Interestingly, at 13% (v/v) HFIP and 30% (v/v) TFE a near-UV CD spectrum approaches the native-like spectral features. Tryptophan fluorescence studies indicate the change in the environment of the tryptophan residues on the addition of HFIP and TFE to acid-unfolded papain. Maximum ANS binding occurs at 13% (v/v) HFIP and 30% (v/v) TFE, suggesting a compact "molten globule"-like conformation with enhanced exposure of hydrophobic surface area. Acid-unfolded papain in presence of 13% (v/v) HFIP and 30% (v/v) TFE showed the recovery of enzymatic activity by 54 and 61%, respectively. Thermal stability of these states was assessed by changes in fluorescence emission maximum and absorbance at 292 nm. Temperature-induced unfolding of papain at pH 2 was non-cooperative and the transition curves were biphasic in nature. Temperature-induced unfolding of HFIP and TFE-induced state was weakly cooperative in comparison to cooperative transition of native.

Archives of Biochemistry and Biophysics, 2006

Concanavalin A (Con A) exists in dimeric state at pH 5. In concentration range 20-60% (v/v) 2,2,2... more Concanavalin A (Con A) exists in dimeric state at pH 5. In concentration range 20-60% (v/v) 2,2,2-trifluoroethanol (TFE) and 2-40% (v/v) 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), Con A at pH 5.0 shows visible aggregation. However, when succinyl Con A was used, no aggregation was observed in the entire concentration range of fluoroalcohols (0-90% v/v TFE and HFIP) and resulted in stable a-helix formation. Temperature-induced concentration-dependent aggregation in Con A was also found to be prevented/reduced in succinylated form. Possible role of electrostatic repulsion among residues in the prevention of hydrophobically driven aggregation has been discussed. Results indicate that succinylation of a protein resulted in greater stability (in both b-sheet and a-helical forms) against alcohol-induced and temperature-induced concentration-dependent aggregation and this observation may play significant role in amyloid-forming proteins. Effect of TFE and HFIP on the conformation of a dimeric protein, Succinylated Con A, has been investigated by circular dichroism (CD), fluorescence emission spectroscopy, binding of hydrophobic dye ANS (8-anilinonaphthalene-1-sulfonic acid). Far UV-CD, a probe for secondary structure shows loss of native secondary structure in the presence of low concentration of both the alcohols, TFE (10% v/v) and HFIP (4% v/v). Upon addition of higher concentration of these alcohols, Succinylated Con A exhibited transformation from b-sheet to a-helical structure. Intrinsic tryptophan fluorescence studies, ANS binding and near UV-CD experiments indicate the protein is more expanded, have more exposed hydrophobic surfaces and highly disrupted tertiary structure at 60% (v/v) TFE and 30% (v/v) HFIP concentrations. Taken together, these results it might be concluded that TFE and HFIP induce two intermediate states at their low and high concentrations in Succinyl Con A.