関: L-methylcysteine hydrochloride

English Journal

Glutathione reductase activity with an oxidized methylated glutathione analog.

Kedrowski BL1, Gutow JH, Stock G, Smith M, Jordan C, Masterson DS.Author information 1Department of Chemistry, University of Wisconsin Oshkosh , Oshkosh, WI , USA and.AbstractAbstract The activity of glutathione reductase with an unnatural analog of oxidized glutathione was explored. The analog, L-γ-glutamyl-2-methyl-L-cysteinyl-glycine disulfide, places an additional methyl group on the alpha position of each of the central cysteine residues, which significantly increases steric bulk near the disulfide bond. Glutathione reductase was completely unable to catalyze the sulfur-sulfur bond reduction of the analog. Additionally, enzyme kinetics experiments indicated that the analog acts as a competitive inhibitor of glutathione reductase. Computational studies confirm that the methylated analog fits within the active site of the enzyme but its disulphide bond geometry is altered, preventing reduction by the enzyme. The substitution of (R)-2-methylcysteine in place of natural (R)-cysteine in peptides constitutes a new strategy for stabilizing disulphide bonds from enzyme-catalyzed degradation.
Journal of enzyme inhibition and medicinal chemistry.J Enzyme Inhib Med Chem.2013 Jul 1. [Epub ahead of print]
Abstract The activity of glutathione reductase with an unnatural analog of oxidized glutathione was explored. The analog, L-γ-glutamyl-2-methyl-L-cysteinyl-glycine disulfide, places an additional methyl group on the alpha position of each of the central cysteine residues, which significantly increa
PMID 23808802

An in vitro investigation of species-dependent intestinal transport of selenium and the impact of this process on selenium bioavailability.

Thiry C1, Ruttens A, Pussemier L, Schneider YJ.Author information 1Biochimie Cellulaire, Nutritionnelle & Toxicologique, Institut des Sciences de la Vie & UCLouvain, Croix du Sud, 5, B1348 Louvain-la-Neuve, Belgium.AbstractA range of Se species has been shown to occur in a variety of different foodstuffs. Depending on its speciation, Se is more or less bioavailable to human subjects. In the present study, the role of speciation as a determinant of Se bioavailability was addressed with an investigation of species-specific mechanisms of transport at the intestinal level. The present work focused on four distinct Se compounds (selenate (Se(VI)), selenite (Se(IV)), selenomethionine (SeMet) and methylselenocysteine (MeSeCys)), whose intestinal transport was mimicked through an in vitro bicameral model of enterocyte-like differentiated Caco-2 cells. Efficiency of Se absorption was shown to be species dependent (SeMet > MeSeCys > Se(VI) > Se(IV)). In the case of SeMet, MeSeCys and Se(VI), the highly polarised passage from the apical to basolateral pole indicated that a substantial fraction of transport was transcellular, whilst results for Se(IV) indicated paracellular diffusion. Passage of the organic Se species (SeMet and MeSeCys) became saturated after 3 h, but no such effect was observed for the inorganic species. In addition, SeMet and MeSeCys transport was significantly inhibited by their respective S analogues methionine and methylcysteine, which suggests a common transport system for both kinds of compounds.
The British journal of nutrition.Br J Nutr.2013 Jun 28;109(12):2126-34. doi: 10.1017/S0007114512004412. Epub 2012 Nov 13.
A range of Se species has been shown to occur in a variety of different foodstuffs. Depending on its speciation, Se is more or less bioavailable to human subjects. In the present study, the role of speciation as a determinant of Se bioavailability was addressed with an investigation of species-speci
PMID 23148951

Intramolecular hydrogen-bonding activation in cysteines: a new effective radical scavenger.

Haya L1, Osante I, Mainar AM, Cativiela C, Urieta JS.Author information 1Group of Applied Thermodynamics and Surfaces (GATHERS), Aragon Institute for Engineering Research (I3A), Universidad de Zaragoza, Zaragoza, Spain.AbstractThe challenge of developing organic molecules with improved antioxidant activities for a competitive marketplace requires, given the great amount of possibilities, much laboratory work. Nowadays, the ability of methodologies based on quantum chemistry to determine the influence of different modifications on a molecule core provides a powerful tool for selecting the most useful derivatives to be synthesized. Here, we report the results of the assessment of antioxidant activity for quaternary amino acids, specifically for cysteine derivatives. The effect of introducing different substituents on the cysteine core is evaluated by using DFT to obtain an adequate structure-antioxidant activity relationship. This theoretical study shows a small panel of targets among which (R)-N-acetyl-2-methylcysteine methyl ester 15 exhibits special features and relevant antioxidant activity. The conformational (1)H NMR study of this synthesized compound indicates the existence of an intramolecular C7 member ring involving S-HO[double bond, length as m-dash]C substructure, which is reported for the first time in the literature for this amino acid unit. This unusual conformation seems to be the reason for the high antioxidant capacity experimentally found for this compound.
Physical chemistry chemical physics : PCCP.Phys Chem Chem Phys.2013 Jun 21;15(23):9407-13. doi: 10.1039/c3cp50743b. Epub 2013 May 13.
The challenge of developing organic molecules with improved antioxidant activities for a competitive marketplace requires, given the great amount of possibilities, much laboratory work. Nowadays, the ability of methodologies based on quantum chemistry to determine the influence of different modifica
PMID 23665681

Japanese Journal

天然アミノ酸S-メチルシステインスルホキシド(SMCS)の機能性とその利用 (特集アミノ酸の機能性)

水道裕久
食品と開発 45(8), 13-15, 2010-08
NAID 40017250667

Relative and Absolute Configuration of Antitumor Agent SW-163D

Nakaya Mino,Oguri Hiroki,Takahashi Kosaku [他],FUKUSHI Eri,WATANABE Kenji,OIKAWA Hideaki
Bioscience, biotechnology, and biochemistry 71(12), 2969-2976, 2007-12-23
… The remaining stereochemistry of the <I>N</I>-methylcysteine moieties was determined from NOE data. …
NAID 10027521978