Disease relevance of beta-Mercaptopyruvic acid

• Cytosolic 3-mercaptopyruvate sulfurtransferases (EC ) of Leishmania major and Leishmania mexicana have been cloned, expressed as active enzymes in Escherichia coli, and characterized [1].
• The basis for this age-related difference in in vivo toxicity was examined by studying biotransformation of KCN to thiocyanate by liver and brain rhodanese (RHO), as well as activity of liver and brain cytochrome oxidase (C-OX), inhibition of C-OX by KCN, and activity of beta-mercaptopyruvate transsulfurase (MT) [2].
• Effect of intraperitoneal administration (12 mmol/kg of body weight) of glucose-cysteine adduct 2-(D-gluco-pentahydroxypentyl)-thiazolidine-4-carboxylate, (glc-cys) on the rhodanese, gamma-cystathionase and 3-mercaptopyruvate sulfurtransferase (MPST) activity levels in guinea pig tissues was studied [3].
• 1. The activity of cysteine aminotransferase (CAT), 3-mercaptopyruvate sulfurtransferase (MPST) and rhodanese is much lower in Ehrlich ascites tumor cells (EATC) than in mouse liver [4].

High impact information on beta-Mercaptopyruvic acid

• The crystal structure of Leishmania major 3-mercaptopyruvate sulfurtransferase. A three-domain architecture with a serine protease-like triad at the active site [5].
• Arg187 is suggested to be a binding site of both mercaptopyruvate and thiosulfate in MST [6].
• Thus, 10 mM solutions of 3-mercaptopyruvate at pH 7.2 lose about 75% of their lactate dehydrogenase reactivity in 90 min at 25 degrees C. The present findings explain the previous observation that 3-mercaptopyruvate exhibits anomalous behavior in transamination with glutamine [7].
• Upon addition of mercaptopyruvate to active PFL, an EPR spectrum is generated which exhibits components from two sulfur-based radicals [8].
• Brain rhodanese and liver beta-mercaptopyruvate sulfurtransferase showed a slight decrease in activity after death [9].

Biological context of beta-Mercaptopyruvic acid

• It is concluded that Arg187 and Arg196 of rat MST are critical residues in determining substrate specificity for mercaptopyruvate [6].
• Steady-state kinetics of 3-mercaptopyruvate sulfurtransferase from bovine kidney [10].
• Further, one immobilized biomimetic dye, bearing mercaptopyruvic acid as biomimetic moiety, displayed the highest purifying ability [11].
• Seasonal variation in the activity of 3-mercaptopyruvate sulphurtransferase of the frog (Rana temporaria) liver [12].
• There are two possible strategies to facilitate MST activities: development of modified mercaptopyruvate with a longer half time and development of a chemical compound which indirectly increases transcription of MST via regulation of a DNA binding protein [13].

Anatomical context of beta-Mercaptopyruvic acid

• A small amount of thiocyanate was produced from cyanide and beta-mercaptopyruvate in the human brain, probably due to contamination with red blood cells [9].
• Three kinds of 3-mercaptopyruvic acid S-conjugate reductase (MPR-I, MPR-II and MPR-III) were purified from rat liver cytosol [14].
• Rat brain mitochondria were found to convert 3-mercaptopyruvate to 2-mercaptoacetate in the presence of NAD+, coenzyme A and thiamin pyrophosphate [15].
• Cysteamine stimulated mucosal 75Se uptake at all intestinal sites tested, whereas the effect of mercaptopyruvate was restricted to the distal jejunum [16].
• 3-mercaptopyruvate sulphurtransferase and rhodanese activities in the developing chick embryo [17].

Associations of beta-Mercaptopyruvic acid with other chemical compounds

• The mercaptopyruvate pathway, in which cysteine or aspartate transaminase catalyzes the transamination from cysteine to 3-mercaptopyruvate and then 3-mercaptopyruvate sulfurtransferase catalyzes the transsulfuration from 3-mercaptopyruvate to pyruvate, also contributes to maintain the cellular redox [18].
• Pyruvate, beta-hydroxypyruvate, beta-mercaptopyruvate, beta-fluoropyruvate, DL-lactate, glycolate, glycoaldehyde, glyoxylate, glyphosate, and DL-aspartate showed no inhibitory effects by steady-state kinetics [19].
• At pH 7.4 the equilibrium between beta-thiopyruvate and beta-thiolactate, in the presence of NADH and lactate dehydrogenase is largely shifted towards the formation of beta-thiolactate as in the case of pyruvate and lactate [20].
• These results suggest that thiosulfate is an intermediate in sulfate formation from D-cysteine and involves the oxidation of D-cysteine by D-amino acid oxidase to form beta-mercaptopyruvate [21].
• In parallel, sulfane sulfur level and activity of rhodanese and 3-mercaptopyruvate sulfurtransferase (MpST) were determined in the mouse brain and liver [22].

Gene context of beta-Mercaptopyruvic acid

• Mercaptopyruvate sulfurtransferase (MST, EC 2.8.1.2) and thiosulfate sulfurtransferase (TST, rhodanese, EC 2.8.1.1) are evolutionarily related enzymes that catalyze the transfer of sulfur ions from mercaptopyruvate and thiosulfate, respectively, to cyanide ions [23].
• 2-Substituted thiazolidine-4(R)-carboxylic acids (TD) were found to increase the concentration of non-protein sulphydryls (NPSH) and the activity of rhodanese (thiosulphate sulphurtransferase, EC 2.8.1.1) and 3-mercaptopyruvate sulphurtransferase (EC 2.8.1.2) in mouse liver [24].
• Recently a sulfurtransferase specific for the substrate 3-mercaptopyruvate was isolated from Arabidopsis thaliana [Papenbrock, J. & Schmidt, A. (2000) Eur. J. Biochem. 267, 145-154] [25].
• To study the mechanism of action of the SSD, the candidate compounds were examined in vitro for their effect on rhodanese and 3-mercaptopyruvate sulfurtransferase (MST) activity under increasing SSD concentrations [26].
• Tissue and intracellular distribution of rhodanese and mercaptopyruvate sulphurtransferase in ruminants and birds [27].

Analytical, diagnostic and therapeutic context of beta-Mercaptopyruvic acid

• Plant mercaptopyruvate sulfurtransferases: molecular cloning, subcellular localization and enzymatic activities [23].
• Site-directed mutagenesis for binding sites of 3-mercaptopyruvate (Arg(187)-->Gly or Arg(196)-->Gly) (J. Biol. Chem. 271 (1996) 27395-27401) did not critically affect the inactivation [28].

References