Shinjiro Tachibana - Academia.edu (original) (raw)

Papers by Shinjiro Tachibana

Monascus pigments have been widely used for food coloring as natural colorant in East Asian count... more Monascus pigments have been widely used for food coloring as natural colorant in East Asian countries. However, the Monascus pigments have a problem of photobleaching which reduces commercial value of the food products. In this study, we investigated whether the Monascus pigments-encapsulated nanoparticles can reduce photobleaching. Hydroxypropyl cellulose (HPC) and poly (lactic-co-glycolic) acid (PLGA) copolymer were used as materials for preparation of nanoparticles. Both Monascus pigments-encapsulated nanoparticles prepared in the present study were obtained excellent dispersibility against water. The particle size of the HPC nanoparticles was smaller than that of the PLGA nanoparticles, whereas the particle diameter distribution of the PLGA nanoparticles was homogeneity rather than that of the HPC nanoparticles. The absorption spectrum of the HPC nanoparticles was similar to that of the original Monascus pigments, but that of the PLGA nanoparticles showed characteristic absorpti...

Microbiological Research, 2022

Monascus spp. are filamentous fungi used in fermented foods. They are also natural colorants and ... more Monascus spp. are filamentous fungi used in fermented foods. They are also natural colorants and food preservatives. Certain metabolites of Monascus spp. lower cholesterol and have other health-promoting effects in humans. In the present study, we demonstrated that the fermentation products of Monascus spp. inhibited ATP synthesis and motility in toxigenic Vibrio cholerae. Single-cell tracking and rotation assays on single flagella showed that Monascus fermentation extract (MFE) significantly impaired V. cholerae swimming by disrupting flagellar rotation. A membrane potential-sensitive carbocyanine dye revealed that MFE depolarized the V. cholerae cell membrane which, in turn, lowered the membrane potential and, by extension, restricted ATP synthesis and flagellar rotation. MFE also severely hindered the motility of other pathogenic bacteria such as V. parahaemolyticus, Pseudomonas aeruginosa, Salmonella enterica Typhimurium, and Leptospira interrogans. The foregoing findings indicate that Monascus fermentation extract could potentially preventing infection caused by multiple pathogenic bacteria as the conventional prophylaxes and slow their progression and lower mortality and morbidity.

Process Biochemistry, 2018

In this research, ovalbumin (OOW), one of the major components in ostrich egg white, was purified... more In this research, ovalbumin (OOW), one of the major components in ostrich egg white, was purified by anion exchange chromatography. Then, the purified OOW was subjected to alkaline hydrolysis (0.25 M NaOH) at 40°C for 2-10 h. The best angiotensin I-converting enzyme (ACE) inhibitory activity was observed at 8 h of hydrolysis. The OOW hydrolysate obtained at 8 h (8 h-hOOW) was purified by the reversed-phase high-performance liquid chromatography (RP-HPLC). The resulting peptide, YV, exhibited an IC 50 value of 63.97 μg/mL. Using a Lineweaver-Burk plot, YV was determined to be a competitive inhibitor, and the inhibition constant (K i) was found to be 55.20 μg/mL. The molecular docking analysis revealed that the binding between YV and the S1 and S2 pocket sites of ACE was mainly stabilized by a hydrogen bond. Moreover, YV maintained ACE inhibitory activity after gastrointestinal digestion and showed no cytotoxic effects on human red blood cells, human keratinocyte cells (HaCaT) and human lung fibroblasts cells (MRC-5). An in vitro test of intestinal absorption showed that YV had a high potential for absorption into the Caco-2 cell monolayer model. Therefore, these results suggest that the YV peptide can be applied for the development of novel natural antihypertensive products.

$Research paper thumbnail of Taste and chemical characteristics of low molecular weight fractions from tofuyo - Japanese fermented soybean curd$

Food chemistry, Jan 30, 2018

Tofuyo, a Japanese traditional food, is a fermented soybean curd manufactured in Okinawa region. ... more Tofuyo, a Japanese traditional food, is a fermented soybean curd manufactured in Okinawa region. Due to its original cheese-like flavor, the current study was designed to evaluate the sensory and chemical characteristics of three stepwise ultrafiltration fractions, using 10,000, 3000 and 500 Da membranes and further chromatographic fractions from tofuyo. The results showed that umami, sweet and salty were the characteristic tastes of all fractions, with umami intensity evaluated for the fraction with MW less than 500 Da (F-500) as the most prominent among the three fractions. Subsequent Sephadex G-25 SF fractions and RP-HPLC fractions were subjected to sensory and chemical analyses. The tastiest fraction contained sodium chloride, sugars, organic acids, umami and sweet free amino acids, at concentrations above their thresholds. The abundant presence of umami and sweet free amino acids with certain concentrations of sodium chloride and glucose might provide the typical savory taste o...

Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures, 2014

Process Biochemistry, 2011

ABSTRACT Recently, we purified two acid proteinases (MpiAP1 and MpiAP2) from Monascus pilosus. In... more ABSTRACT Recently, we purified two acid proteinases (MpiAP1 and MpiAP2) from Monascus pilosus. In this study, we examine the potential application of these enzymes in the production of low-antigen whey protein. Hydrolysates of whey protein concentrate (WPC) were prepared enzymatically using MpiAP1, MpiAP2, pepsin and trypsin, both singly, and in combination. The electrophoretic analyses of WPC degradation showed that casein is the component most favored by all enzymes. The α-lactalbumin was completely digested by fungal acid proteinases but not by gastrointestinal proteinases, and β-lactoglobulin was effectively digested by trypsin only. The complete digestion of all WPC components was accomplished with the addition of trypsin to partially hydrolyzed WPC treated with Monascus acid proteinases. The lowest antigenicity was observed in the WPC hydrolysates treated with MpiAP1/MpiAP2 and trypsin by competitive ELISA. Our results suggest that Monascus acid proteinases can be effectively used to make hypoallergenic bovine milk whey protein hydrolysates.

Journal of Food Science and Technology, 2014

In this work, chemical and biological characteristics of two types of Thai fermented shrimp paste... more In this work, chemical and biological characteristics of two types of Thai fermented shrimp paste, Kapi Ta Dam and Kapi Ta Deang, at different fermentation periods and their raw materials were investigated. Kapi had low water activity and high proteins with high glutamic acid and lysine. Both Kapis, which had different sources, showed similar characteristics. The number of lactic acid bacteria in the products increased during the early stages of fermentation. Free α-amino acid contents in the products increased with the fermentation time. The water extracts from Kapi products showed strong antioxidative activities against ABTS + radical, and ACE inhibitory activity but they did not exhibit antimicrobial activity against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella Typhimurium. Biological activities in Kapi could be developed by fermentation process, enzymatic hydrolysis of proteins and non-enzymatic browning reactions. Kapi could, thus, serve as a potential source of natural bioactive substances.

Toxicology Letters, 2008

Gene expression analysis using customized or focused DNA microarrays is favorable because of a re... more Gene expression analysis using customized or focused DNA microarrays is favorable because of a reduction in the cost and time needed for the analysis. To examine the effect of chemicals on the liver, we developed an in-house cDNA microarray system, mouse Liver Stress Array ver. 1.0, containing 355 unique genes involved in drug metabolism, inflammation and liver-related proteins. These genes were selected for sensing the homeostasis of the liver and based on the information of liver transcriptome revealed by serial analysis of gene expression. By using this customized microarray, we analyzed gene expression changes in the mouse liver treated by 11 known hepatotoxicants. Gene expression measurements corresponding to the in vivo response to known hepatotoxicants revealed that profiles of chemicals with similar mechanisms clustered together. For each of the chemicals tested, several genes that were induced or repressed were common in each chemical exposure, whereas other genes were unique for the specific class compound. Ingenuity pathways analysis revealed that significant alterations in gene expression occurred in a number of biological networks by these treatments. Although the genes spotted on our array was limited to a highly focused set for toxicity classification, this work provides proof of concept that patterns of gene regulation assessed by a focused array system are useful to classify unknown chemicals.

The Tohoku Journal of Experimental Medicine, 2011

In vitro gene expression profiling with isolated hepatocytes has been used to assess the hepatoto... more In vitro gene expression profiling with isolated hepatocytes has been used to assess the hepatotoxicity of certain chemicals because of animal welfare issues. However, whether an in vitro system can completely replace the in vivo system has yet to be elucidated in detail. Using a focused microarray established in our laboratory, we examined gene expression profiles in the mouse liver and primary cultured hepatocytes after treatment with different doses of acetaminophen, a widely used analgesic that frequently causes liver injury. The acute hepatotoxicity of acetaminophen was confirmed by showing the induction of an oxidative stress marker, heme oxygenase-1, elevated levels of serum transaminase, and histopathological findings. In vivo microarray and network analysis showed that acetaminophen treatment provoked alterations in relation to the inflammatory response, and that tumor necrosis factor-α plays a central role in related pathway alterations. By contrast, pathway analyses in in vitro isolated hepatocytes did not find such prominent changes in the inflammation-related networks compared with the in vivo situation. Thus, although in vitro gene expression profiles are useful for evaluating the direct toxicity of chemicals, indirect toxicities including inflammatory responses mediated by cell-cell interactions or secondary toxicity due to pathophysiological changes in the whole body may be overlooked. Our results indicate that the in vitro hepatotoxicity prediction system using isolated hepatocytes does not fully reflect the in vivo cellular response. An in vitro system may be appropriate, therefore, for high throughput screening to detect the direct hepatotoxicity of a test compound.

Sensors and Actuators B: Chemical, 2008

... Reynaldo Villalonga a , Akira Fujii b , Hiroaki Shinohara c , Shinjiro Tachibana d and Yasuhi... more ... Reynaldo Villalonga a , Akira Fujii b , Hiroaki Shinohara c , Shinjiro Tachibana d and Yasuhisa Asano d , Corresponding Author Contact Information , E-mail The Corresponding Author [Author vitae]. ... [3] Z. Ding, CO Harding and B. Thöny, State-of-the-art 2003 on PKU gene ...

Microbiology, 2006

A gene for periplasmic poly(vinyl alcohol) (PVA) dehydrogenase (PVADH) was cloned, based on the N... more A gene for periplasmic poly(vinyl alcohol) (PVA) dehydrogenase (PVADH) was cloned, based on the N-terminal amino acid sequence of the purified PVADH from Sphingomonas sp. 113P3 and the sequence of the gene for PVADH (pvaA, GenBank accession no. AB190288). The recombinant PVADH tagged with hexahistidine was expressed in Escherichia coli and purified to homogeneity. The recombinant enzyme had the same characteristics as the purified enzyme from Sphingomonas sp. strain 113P. In addition to PVA, the recombinant PVADH could oxidize glycols such as polypropylene glycols and 1,3-butane/cyclohexanediol and 2,4-pentanediol, but neither primary nor secondary alcohols. The amino acid sequence of the recombinant PVADH showed similarity with those of PVADH from Pseudomonas sp. strain VM15C, putative PVADHs from Azoarcus sp. EbN1, and Xanthomonas species (54–25 % identity), and the quinohaemoprotein alcohol dehydrogenases (QH-ADHs) from Comamonas testosteroni, Ralstonia eutropha and Pseudomonas p...

Journal of Industrial Microbiology & Biotechnology, 2011

An acid proteinase from Monascus purpureus No. 3403, MpuAP, was previously purified and some char... more An acid proteinase from Monascus purpureus No. 3403, MpuAP, was previously purified and some characterized in our laboratory (Agric Biol Chem 48:1637-1639, 1984). However, further information about this enzyme is lacking. In this study, we investigated MpuAP&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s comprehensive substrate specificity, storage stability, and prospects for reducing antigenicity of whey proteins for application in the food industry. MpuAP hydrolyzed primarily five peptide bonds, Gln(4)-His(5), His(10)-Leu(11), Ala(14)-Leu(15), Gly(23)-Phe(24) and Phe(24)-Phe(25) in the oxidized insulin B-chain. The lyophilized form of the enzyme was well preserved at 30-40°C for 7 days without stabilizers. To investigate the possibility of reducing the antigenicity of the milk whey protein, enzymatic hydrolysates of the whey protein were evaluated by inhibition ELISA. Out of the three main components of whey protein, casein and α-lactalbumin were efficiently degraded by MpuAP. The sequential reaction of MpuAP and trypsin against the whey protein successfully degraded casein, α-lactalbumin and β-lactoglobulin with the highest degree of hydrolysis. As a result, the hydrolysates obtained by using the MpuAP-trypsin combination showed the lowest antigenicity compared with the single application of pepsin, trypsin or pepsin-trypsin combination. Therefore, the overall result suggested that the storage-stable MpuAP and trypsin combination will be a productive approach for making hypoallergic bovine milk whey protein hydrolysates.

Journal of Experimental Nanoscience, 2006

Native and adamantane-modified L-phenylalanine dehydrogenase was immobilised on b-cyclodextrin co... more Native and adamantane-modified L-phenylalanine dehydrogenase was immobilised on b-cyclodextrin coated gold nanospheres via supramolecular associations. The amount of immobilised protein was estimated to be about 100-110 mg per milligram of support. The nanocatalyst retained high catalytic activity and showed increased affinity for the substrate. Both immobilised enzymes showed fluorescence emission spectra similar to that of the native protein counterpart. The range of optimum pH for catalytic activity was increased from 11.5 to 11.5-12.5 for the native and adamantane-modified enzymes after adsorption on gold nanospheres. Immobilised native and modified L-phenylalanine dehydrogenase retained about 20% and 41%, respectively, of the initial activity after 10 cycles of reuse. These results open a new perspective to the possible application of cyclodextrin-modified gold nanospheres as water-soluble carriers for enzyme immobilisation.

FEMS Microbiology Letters, 2003

Previous work has shown that when the bacterium Stenotrophomonas maltophilia is grown on polyprop... more Previous work has shown that when the bacterium Stenotrophomonas maltophilia is grown on polypropylene glycol, different dye-linked polypropylene glycol dehydrogenase (PPG-DH) activities are induced during growth. Here the purification and characterization of the dehydrogenase activity induced in the stationary phase, and present in the periplasmic space, is described. The homogeneous enzyme preparation obtained consists of a homodimeric protein with a molecular mass of about 123 kDa and an isoelectric point of 5.9. The cofactor of the enzyme appeared to be pyrroloquinoline quinone (PQQ), no heme c was present, and holo-enzyme contained two PQQ molecules per enzyme molecule. In these respects, PPG-DH described here is similar to already known quinoprotein alcohol dehydrogenases, but in other respects, it is different. Therefore, it is suggested that PPG-DH could be a new type of quinoprotein alcohol dehydrogenase. Based on its strong preference for polyols, PPG-DH seems well fitted to carry out the first step in the degradation of PPGs, synthetic polymers containing a variety of hydroxyl groups.

Enzyme and Microbial Technology, 2007

... This research was supported by grants from The Japan Society for the Promotion of Sciences to... more ... This research was supported by grants from The Japan Society for the Promotion of Sciences to R. Villalonga and Y. Asano (Grant S-04257), and from Toyama Medical-Bio Cluster (The Ministry of Education, Culture, Sports, Science and Technology, Japan) to Y. Asano and S ...

Environmental Health and Preventive Medicine, 2009

Objectives We have attempted to upgrade and validate an in-house cDNA microarray system developed... more Objectives We have attempted to upgrade and validate an in-house cDNA microarray system developed by our group for the evaluation of chemical toxicity. Methods To establish an in-house microarray, we selected genes that play pivotal roles in detoxifying exogenous substances and maintaining homeostasis in the liver. To validate the system, we examined gene expression profiles in mouse liver following treatment with different doses of carbon tetrachloride (CCl 4). The data were also analyzed by pathway analysis tools. Results We upgraded our array system by collecting genes that are responsive to xenobiotic receptors, apoptosis-related genes, and stress-responsive genes. The acute toxicity of CCl 4 was confirmed by elevated levels of serum transaminase and histopathological findings. The microarray data showed the CCl 4 treatment induced significant changes in gene expression in the mouse liver, and the ingenuity pathways analysis revealed alterations in gene expression in inflammation-related networks. Conclusions We have established a focused microarray system that may be useful for use in toxicogenomics studies. Using this array system, we gained insight into the mechanisms by which CCl 4 exerts its toxic effects. The results of our study also indicate that the combination of focused arrays and bioinformatics tools is helpful in the mechanistic analysis of chemical toxicity.