Alex Khomutov - Academia.edu (original) (raw)
Papers by Alex Khomutov
Biomolecules, Dec 22, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
(methyl)sulphonium](https://attachments.academia-assets.com/119801021/thumbnails/1.jpg)
](Biochemical Journal, Aug 1, 1991
Amino-oxy)ethyl](5'-deoxyadenosin-5'-yl)(methyl)sulphonium, the amino-oxy analogue of decarboxyla... more Amino-oxy)ethyl](5'-deoxyadenosin-5'-yl)(methyl)sulphonium, the amino-oxy analogue of decarboxylated Sadenosylmethionine, is a potent irreversible inhibitor of Escherichia coli S-adenosylmethionine decarboxylase [Khomutov,
Russian Journal of Bioorganic Chemistry, Nov 1, 2019
Biogenic polyamines spermine and spermidine are present in eukaryotic cells in micro-and millimol... more Biogenic polyamines spermine and spermidine are present in eukaryotic cells in micro-and millimolar concentrations, that determines the multiplicity of their functions and the necessity to support normal cell growth. Analogs and derivatives of spermine and spermidine are widely used in biochemistry of polyamines, a number of fundamentally significant results for the field were obtained with their help. C-methylated analogs of polyamines are unique, since among these compounds functionally active in vitro and in vivo spermidine and spermine mimetics were found. Biochemical properties of the compounds of this family can be regulated by moving the methyl group along the backbone of a polyamine and/or changing the configuration of the chiral center. The peculiarities of the interaction of C-methylated analogs of polyamines with the enzymes of their metabolism, the activity in the cell culture and the methods of synthesizing these compounds are discussed.
Acta Naturae, Oct 27, 2020
Homeostasis of the biogenic polyamines spermine (Spm) and spermidine (Spd), present in μM-mM conc... more Homeostasis of the biogenic polyamines spermine (Spm) and spermidine (Spd), present in μM-mM concentrations in all eukaryotic cells, is precisely regulated by coordinated activities of the enzymes of polyamine synthesis, degradation, and transport, in order to sustain normal cell growth and viability. Spermine oxidase (SMOX) is the key and most recently discovered enzyme of polyamine metabolism that plays an essential role in regulating polyamine homeostasis by catalyzing the back-conversion of Spm to Spd. The development of many types of epithelial cancer is associated with inflammation, and disease-related inflammatory stimuli induce SMOX. MDL72527 is widely used in vitro and in vivo as an irreversible inhibitor of SMOX, but it is also potent towards N 1-acetylpolyamine oxidase. Although SMOX has high substrate specificity, Spm analogues have not been systematically studied as enzyme inhibitors. Here we demonstrate that 1,12-diamino-2,11-bis(methylidene)-4,9-diazadodecane (2,11-Met 2-Spm) has, under standard assay conditions, an IC 50 value of 169 μM towards SMOX and is an interesting instrument and lead compound for studying polyamine catabolism.
Russian Chemical Bulletin, Aug 1, 1996
Approaches to the synthesis of 1-amino- and 2-amino-2-carboxyethylphosphinic and-phosphoric acids... more Approaches to the synthesis of 1-amino- and 2-amino-2-carboxyethylphosphinic and-phosphoric acids have been studied. A convenient method for the preparation of phosphinic acids is the reactions of ethyl diethoxymethylphosphonite with ethyl acetamidomethylenemalonate and ethyl 2-acetamidoacrylate.
Journal of Biological Chemistry, Aug 1, 1988
Chemischer Informationsdienst, May 6, 1986
Mendeleev Communications, Sep 1, 2018
European journal of biochemistry, Mar 1, 1991
ABSTRACT A potent irreversible inhibitor of S-adenosylmethionine (AdoMet) decarboxylase, S-(5&... more ABSTRACT A potent irreversible inhibitor of S-adenosylmethionine (AdoMet) decarboxylase, S-(5'-adenosyl)-methylthio-2-aminooxyethane (AdoMeSaoe), was used to study the regulatory control of this key enzyme in the polyamine biosynthetic pathway. Treatment of L1210 cells with the inhibitor completely eradicated the growth-induced rise in AdoMet decarboxylase activity, resulting in a marked decrease in cellular content of spermidine and spermine. The putrescine content, on the other hand, was greatly elevated. Although no detectable AdoMet decarboxylase activity was found in the L1210 cells after treatment with AdoMeSaoe, the cells contained 50-fold higher amounts of AdoMet decarboxylase protein, compared to untreated cells during exponential growth. Part of this increase was shown to be due to elevated synthesis of the enzyme. This stimulation appeared to be related to the decrease in cellular spermidine and spermine content, since addition of either one of the polyamines counteracted the rise in AdoMet decarboxylase synthesis. The synthesis rate was determined by immunoprecipitation of labeled enzyme after a short pulse with [35S]methionine. In addition to a protein that co-migrated with pure rat AdoMet decarboxylase (Mr approximately 32,000), the antibody precipitated a somewhat larger labeled protein (Mr approximately 37,000) that most likely represents the proenzyme form. Treatment of the L1210 cells with AdoMetSaoe also gave rise to a marked stabilization of the decarboxylase which contributed to the increase in its cellular protein content. Addition of spermidine did not significantly affect this stabilization, whereas the addition of spermine reduced the half-life of the enzyme to almost that of the control cells.
Biochemical Journal, Jul 12, 2013
We have shown previously that the polyamine spermidine is indispensable for differentiation of 3T... more We have shown previously that the polyamine spermidine is indispensable for differentiation of 3T3-L1 preadipocytes. In the present study, we examined the mechanism of spermidine function by using the polyamine biosynthesis inhibitor αdifluoromethylornithine in combination with the metabolically stable polyamine analogues γ-methylspermidine or (R,R)α,ω-bismethylspermine. At the early phase of differentiation, spermidine-depleted 3T3-L1 cells showed decreased translation of the transcription factor C/EBPβ (CCAAT/enhancer-binding protein β), decreased PP2A (protein phosphatase 2A) activity and increased cytoplasmic localization of the RNA-binding protein HuR (human antigen R). The amount of HuR bound to C/EBPβ mRNA was reduced, whereas the amount of bound CUGBP2, an inhibitor of C/EBPβ translation, was increased. ANP32 (acidic nuclear phosphoprotein 32) proteins, which are known PP2A inhibitors and HuR ligands, bound more PP2A and HuR in spermidine-depleted than in control cells, whereas immunodepletion of ANP32 proteins from the lysate of spermidine-depleted cells restored PP2A activity. Taken together, our data shows that spermidine promotes C/EBPβ translation in differentiating 3T3-L1 cells, and that this process is controlled by the interaction of ANP32 with HuR and PP2A.
Russian Journal of Bioorganic Chemistry, Dec 1, 2006
Convenient methods of synthesis of 1-aminooxy-3,8-diaza-11-aminoundecane, its earlier unknown N1-... more Convenient methods of synthesis of 1-aminooxy-3,8-diaza-11-aminoundecane, its earlier unknown N1-and N1 -acetyl derivatives, and also 1,10-bis(aminooxy)-3,8-diazadecane are suggested. It is shown a possibility to selectively delete the acid-labile ethoxyethylidene protection of aminooxy group by hydrosulfates in the presence of N-tert-butyloxycarbonyl group.
Journal of Molecular Structure, May 1, 2001
The interaction of highly polymerized calf-thymus DNA with 1-aminooxy-3-N-(3-aminopropyl)-aminopr... more The interaction of highly polymerized calf-thymus DNA with 1-aminooxy-3-N-(3-aminopropyl)-aminopropane (ap-apa), an aminooxy analogue of the biogenic ornithine-derived polyamine spermidine, has been investigated by vibrational spectroscopy. Infrared and Raman spectra of DNA/ap-apa solutions, at different polyamine concentrations, were registered. The infrared spectra were extended to solutions in heavy water in order to analyze the 1500±1700 cm 21 region. The spectroscopical data were discussed in terms of preferential binding sites between DNA and the aminooxy polyamine. The results support the existence of structural speci®ties in the interaction, at least under our experimental conditions; they also indicate differences at low and high ap-apa concentrations, which involve mainly base residues.
Amino Acids, Aug 2, 2011
The polyamines, spermidine and spermine, are abundant organic cations participating in many impor... more The polyamines, spermidine and spermine, are abundant organic cations participating in many important cellular processes. We have previously shown that the rate-limiting enzyme of polyamine catabolism, spermidine/spermine N(1)-acetyltransferase (SSAT), has an alternative mRNA splice variant (SSATX) which undergoes degradation via nonsense-mediated mRNA decay (NMD) pathway, and that the intracellular polyamine level regulates the ratio of the SSATX and SSAT splice variants. The aim of this study was to investigate the effect of SSATX level manipulation on SSAT activity in cell culture, and to examine the in vivo expression levels of SSATX and SSAT mRNA. Silencing SSATX expression with small interfering RNA led to increased SSAT activity. Furthermore, transfection of SSAT-deficient cells with mutated SSAT gene (which produced only trace amount of SSATX) yielded higher SSAT activity than transfection with natural SSAT gene (which produced both SSAT and SSATX). Blocking NMD in vivo by protein synthesis inhibitor cycloheximide resulted in accumulation of SSATX mRNA, and like in cell culture, the increase of SSATX mRNA was prevented by administration of polyamine analog N(1),N(11)-diethylnorspermine. Although SSATX/total SSAT mRNA ratio did not correlate with polyamine levels or SSAT activity between different tissues, increasing polyamine levels in a given tissue led to decreased SSATX/total SSAT mRNA ratio and vice versa. Taken together, the regulated unproductive splicing and translation of SSAT has a physiological relevance in modulating SSAT activity. However, in addition to polyamine level there seems to be additional factors regulating tissue-specific alternative splicing of SSAT.
Biomolecules, Dec 22, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Biochemical Journal, Aug 1, 1991
Amino-oxy)ethyl](5'-deoxyadenosin-5'-yl)(methyl)sulphonium, the amino-oxy analogue of decarboxyla... more Amino-oxy)ethyl](5'-deoxyadenosin-5'-yl)(methyl)sulphonium, the amino-oxy analogue of decarboxylated Sadenosylmethionine, is a potent irreversible inhibitor of Escherichia coli S-adenosylmethionine decarboxylase [Khomutov,
Russian Journal of Bioorganic Chemistry, Nov 1, 2019
Biogenic polyamines spermine and spermidine are present in eukaryotic cells in micro-and millimol... more Biogenic polyamines spermine and spermidine are present in eukaryotic cells in micro-and millimolar concentrations, that determines the multiplicity of their functions and the necessity to support normal cell growth. Analogs and derivatives of spermine and spermidine are widely used in biochemistry of polyamines, a number of fundamentally significant results for the field were obtained with their help. C-methylated analogs of polyamines are unique, since among these compounds functionally active in vitro and in vivo spermidine and spermine mimetics were found. Biochemical properties of the compounds of this family can be regulated by moving the methyl group along the backbone of a polyamine and/or changing the configuration of the chiral center. The peculiarities of the interaction of C-methylated analogs of polyamines with the enzymes of their metabolism, the activity in the cell culture and the methods of synthesizing these compounds are discussed.
Acta Naturae, Oct 27, 2020
Homeostasis of the biogenic polyamines spermine (Spm) and spermidine (Spd), present in μM-mM conc... more Homeostasis of the biogenic polyamines spermine (Spm) and spermidine (Spd), present in μM-mM concentrations in all eukaryotic cells, is precisely regulated by coordinated activities of the enzymes of polyamine synthesis, degradation, and transport, in order to sustain normal cell growth and viability. Spermine oxidase (SMOX) is the key and most recently discovered enzyme of polyamine metabolism that plays an essential role in regulating polyamine homeostasis by catalyzing the back-conversion of Spm to Spd. The development of many types of epithelial cancer is associated with inflammation, and disease-related inflammatory stimuli induce SMOX. MDL72527 is widely used in vitro and in vivo as an irreversible inhibitor of SMOX, but it is also potent towards N 1-acetylpolyamine oxidase. Although SMOX has high substrate specificity, Spm analogues have not been systematically studied as enzyme inhibitors. Here we demonstrate that 1,12-diamino-2,11-bis(methylidene)-4,9-diazadodecane (2,11-Met 2-Spm) has, under standard assay conditions, an IC 50 value of 169 μM towards SMOX and is an interesting instrument and lead compound for studying polyamine catabolism.
Russian Chemical Bulletin, Aug 1, 1996
Approaches to the synthesis of 1-amino- and 2-amino-2-carboxyethylphosphinic and-phosphoric acids... more Approaches to the synthesis of 1-amino- and 2-amino-2-carboxyethylphosphinic and-phosphoric acids have been studied. A convenient method for the preparation of phosphinic acids is the reactions of ethyl diethoxymethylphosphonite with ethyl acetamidomethylenemalonate and ethyl 2-acetamidoacrylate.
Journal of Biological Chemistry, Aug 1, 1988
Chemischer Informationsdienst, May 6, 1986
Mendeleev Communications, Sep 1, 2018
European journal of biochemistry, Mar 1, 1991
ABSTRACT A potent irreversible inhibitor of S-adenosylmethionine (AdoMet) decarboxylase, S-(5&... more ABSTRACT A potent irreversible inhibitor of S-adenosylmethionine (AdoMet) decarboxylase, S-(5'-adenosyl)-methylthio-2-aminooxyethane (AdoMeSaoe), was used to study the regulatory control of this key enzyme in the polyamine biosynthetic pathway. Treatment of L1210 cells with the inhibitor completely eradicated the growth-induced rise in AdoMet decarboxylase activity, resulting in a marked decrease in cellular content of spermidine and spermine. The putrescine content, on the other hand, was greatly elevated. Although no detectable AdoMet decarboxylase activity was found in the L1210 cells after treatment with AdoMeSaoe, the cells contained 50-fold higher amounts of AdoMet decarboxylase protein, compared to untreated cells during exponential growth. Part of this increase was shown to be due to elevated synthesis of the enzyme. This stimulation appeared to be related to the decrease in cellular spermidine and spermine content, since addition of either one of the polyamines counteracted the rise in AdoMet decarboxylase synthesis. The synthesis rate was determined by immunoprecipitation of labeled enzyme after a short pulse with [35S]methionine. In addition to a protein that co-migrated with pure rat AdoMet decarboxylase (Mr approximately 32,000), the antibody precipitated a somewhat larger labeled protein (Mr approximately 37,000) that most likely represents the proenzyme form. Treatment of the L1210 cells with AdoMetSaoe also gave rise to a marked stabilization of the decarboxylase which contributed to the increase in its cellular protein content. Addition of spermidine did not significantly affect this stabilization, whereas the addition of spermine reduced the half-life of the enzyme to almost that of the control cells.
Biochemical Journal, Jul 12, 2013
We have shown previously that the polyamine spermidine is indispensable for differentiation of 3T... more We have shown previously that the polyamine spermidine is indispensable for differentiation of 3T3-L1 preadipocytes. In the present study, we examined the mechanism of spermidine function by using the polyamine biosynthesis inhibitor αdifluoromethylornithine in combination with the metabolically stable polyamine analogues γ-methylspermidine or (R,R)α,ω-bismethylspermine. At the early phase of differentiation, spermidine-depleted 3T3-L1 cells showed decreased translation of the transcription factor C/EBPβ (CCAAT/enhancer-binding protein β), decreased PP2A (protein phosphatase 2A) activity and increased cytoplasmic localization of the RNA-binding protein HuR (human antigen R). The amount of HuR bound to C/EBPβ mRNA was reduced, whereas the amount of bound CUGBP2, an inhibitor of C/EBPβ translation, was increased. ANP32 (acidic nuclear phosphoprotein 32) proteins, which are known PP2A inhibitors and HuR ligands, bound more PP2A and HuR in spermidine-depleted than in control cells, whereas immunodepletion of ANP32 proteins from the lysate of spermidine-depleted cells restored PP2A activity. Taken together, our data shows that spermidine promotes C/EBPβ translation in differentiating 3T3-L1 cells, and that this process is controlled by the interaction of ANP32 with HuR and PP2A.
Russian Journal of Bioorganic Chemistry, Dec 1, 2006
Convenient methods of synthesis of 1-aminooxy-3,8-diaza-11-aminoundecane, its earlier unknown N1-... more Convenient methods of synthesis of 1-aminooxy-3,8-diaza-11-aminoundecane, its earlier unknown N1-and N1 -acetyl derivatives, and also 1,10-bis(aminooxy)-3,8-diazadecane are suggested. It is shown a possibility to selectively delete the acid-labile ethoxyethylidene protection of aminooxy group by hydrosulfates in the presence of N-tert-butyloxycarbonyl group.
Journal of Molecular Structure, May 1, 2001
The interaction of highly polymerized calf-thymus DNA with 1-aminooxy-3-N-(3-aminopropyl)-aminopr... more The interaction of highly polymerized calf-thymus DNA with 1-aminooxy-3-N-(3-aminopropyl)-aminopropane (ap-apa), an aminooxy analogue of the biogenic ornithine-derived polyamine spermidine, has been investigated by vibrational spectroscopy. Infrared and Raman spectra of DNA/ap-apa solutions, at different polyamine concentrations, were registered. The infrared spectra were extended to solutions in heavy water in order to analyze the 1500±1700 cm 21 region. The spectroscopical data were discussed in terms of preferential binding sites between DNA and the aminooxy polyamine. The results support the existence of structural speci®ties in the interaction, at least under our experimental conditions; they also indicate differences at low and high ap-apa concentrations, which involve mainly base residues.
Amino Acids, Aug 2, 2011
The polyamines, spermidine and spermine, are abundant organic cations participating in many impor... more The polyamines, spermidine and spermine, are abundant organic cations participating in many important cellular processes. We have previously shown that the rate-limiting enzyme of polyamine catabolism, spermidine/spermine N(1)-acetyltransferase (SSAT), has an alternative mRNA splice variant (SSATX) which undergoes degradation via nonsense-mediated mRNA decay (NMD) pathway, and that the intracellular polyamine level regulates the ratio of the SSATX and SSAT splice variants. The aim of this study was to investigate the effect of SSATX level manipulation on SSAT activity in cell culture, and to examine the in vivo expression levels of SSATX and SSAT mRNA. Silencing SSATX expression with small interfering RNA led to increased SSAT activity. Furthermore, transfection of SSAT-deficient cells with mutated SSAT gene (which produced only trace amount of SSATX) yielded higher SSAT activity than transfection with natural SSAT gene (which produced both SSAT and SSATX). Blocking NMD in vivo by protein synthesis inhibitor cycloheximide resulted in accumulation of SSATX mRNA, and like in cell culture, the increase of SSATX mRNA was prevented by administration of polyamine analog N(1),N(11)-diethylnorspermine. Although SSATX/total SSAT mRNA ratio did not correlate with polyamine levels or SSAT activity between different tissues, increasing polyamine levels in a given tissue led to decreased SSATX/total SSAT mRNA ratio and vice versa. Taken together, the regulated unproductive splicing and translation of SSAT has a physiological relevance in modulating SSAT activity. However, in addition to polyamine level there seems to be additional factors regulating tissue-specific alternative splicing of SSAT.