Disease relevance of MPST

• Expression of both enzymes was focally lost in ulcerative colitis and markedly reduced in advanced colon cancer, the disease progression correlating with the decreased expression of MST and TST [1].
• Tissues other than the liver and kidney are more susceptible to cyanide toxicity because they contain less MST and rhodanese [2].
• E. coli C32S Trx, however, did not activate MST [3].
• Six of 7 dogs receiving 2.0 mg/kg/day 6-MP i.a. (MST = 12 days) developed azotemia secondary to drug-induced nephrotoxicity [4].
• From the End Results Group file at the National Cancer Institute, 9,745 colorectal cancer patients diagnosed from 1965 through 1971 and classified as adenocarcinoma NOS were selected to evaluate the joint effect of various prognostic factors on MST [5].

High impact information on MPST

• These results indicate that 3-MST and GAPDH have more suitable potentials as a physiological selenium-delivery protein than rhodanese [6].
• 3-Mercaptopyruvate sulfurtransferase (3-MST; EC 2.8.1.2) and GAPDH also bound selenium supplied as selenodiglutathione formed from SeO3(2-) and glutathione [6].
• When participants monitored the peripheral visual field, greater recruitment (as measured by functional magnetic resonance imaging) of the motion-selective area MT/MST was observed in deaf than in hearing individuals, whereas the two groups were comparable when attending to the central visual field [7].
• Rat 3-mercaptopyruvate sulfurtransferase (MST) contains three exposed cysteines as follows: a catalytic site cysteine, Cys(247), in the active site and Cys(154) and Cys(263) on the surface of MST [3].
• On the other hand, reduced glutathione did not affect MST activity [3].

Chemical compound and disease context of MPST

• E. coli C35S Trx, in which Cys(35) was replaced with Ser, formed some adducts with MST and activated MST after treatment with DTT [3].
• In this paper we evaluate the cytokine expression patterns of T-cells and the plasmatic levels of nitrite and nitrate in patients with localized cutaneous leishmaniasis (LCL) as well as endemic non-infected individuals with positive (MST) and negative (NI) Montenegro skin test, without previous history of leishmanial lesions [8].

Biological context of MPST

• In such tissues as the liver or gonads, high GSH levels and high activities of MPST (in the liver) or MPST and rhodanese (in the gonads) seemed to accompany protein biosynthesis during hibernation [9].
• This work constitutes the first report of the existence of a functional genetic polymorphism affecting MPST and should be of great help to investigate certain disorders such as MCDU [10].
• Two intronic polymorphisms (IVS1-110C>G and IVS2+39C>T) and a nonsense mutation (Tyr(85)Stop) were identified and their functional consequences were assessed in vivo by measurement of erythrocyte MPST activity and/or in vitro using heterologous expression or transient transfection assay [10].
• 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 [11].
• Reduced Trx turns on a redox switch for the enzymatic activation of MST, which contributes to the maintenance of cellular redox homeostasis [3].

Anatomical context of MPST

• MST then detoxifies cyanide again in cooperation with rhodanese in mitochondria [2].
• In such tissues as the testes, muscles and heart, the level of GSH and the activity of 3-mercaptopyruvate sulfurtransferase were significantly diminished [12].
• The distribution of mercaptopyruvate sulfurtransferase (EC 2.8.1.2) in human blood cell compartments has been studied [13].
• It is potentially applicable to motion-sensitive neurons with highly structured receptive fields, such as those in the optic tectum of the pigeon or in area MST of the monkey [14].
• Areas MT/MST and STS in the posterior part of the temporal lobe responded either to serve and to non-serve stimuli, relative to static controls [15].

Associations of MPST with chemical compounds

• Using specific antisera to discriminate TST from MST, we found that only TST could detoxify H2S [1].
• Mercaptopyruvate sulfurtransferase (MPST) plays a central role in both cysteine degradation and cyanide detoxification [10].
• Phenylpyruvate was the most effective inhibitor, reducing activity to 0.2% of control values in the extract, and 11% of control values for purified MPST when added to the reaction at 30 mM [16].
• Some investigators have attempted a new therapy in which mercaptopyruvate, a substrate of MST was administered intravenously, but this was not effective for detoxification due to the rapid decomposition of mercaptopyruvate in the blood [11].
• On the other hand, nitrite and cobalt EDTA did not affect MST [11].

Other interactions of MPST

• 3-Mercaptopyruvate sulfurtransferase serves as an antioxidant protein: when the enzyme is exposed to stoichiometric amounts of the oxidant hydrogen peroxide, it is inhibited via the formation of low redox sulfenate at the catalytic site cysteine [17].

Analytical, diagnostic and therapeutic context of MPST

• The techniques of neuronal disconnection included multiple subpial resection (MST), corpus callosotomy. and functional hemispherectomy by disconnection [18].
• In a double-blind investigation the effect of oral controlled-release morphine (MST 30 mg) on pre-operative anxiety was assessed in 50 patients undergoing cholecystectomy [19].
• MXL capsules were shown to provide effective analgesia over the 24-h dosing interval which was comparable to that of MST Continus tablets administered twice daily [20].
• A randomized crossover study comparing the efficacy and tolerability of a novel once-daily morphine preparation (MXL capsules) with MST Continus tablets in cancer patients with severe pain [20].
• The Cooper test had a correlation with the treadmill test of 0.92, while the MST and the predictedL/E had correlations of 0.86 and 0.76 respectively [21].

References