Coffee Caffeine Molecule Chemical structure Molecular geometry, Coffee, angle, white, text png 1200x987px 40.58KB.black and white ball illustration, Molecule Chemistry Molecular geometry Chemical structure, molecule, blue, text, color png 2482x1761px 300.48KB.Sulfur dioxide Chemistry Lewis structure Molecule, Sulfur Dioxide, text, chemistry, number png 1280圆03px 28.95KB.Lewis structure Ammonia Molecular geometry Molecule Ammonium, others, electron, chemistry, structure png 777圆00px 134.05KB.Carbon dioxide Structural formula Molecule Carbon monoxide, chemical formulas, angle, text, carbon png 1700x500px 6.01KB.Oxygen Ozone Molecule Hydrogen peroxide Atom, others, atom, o 2, o 3 png 600圆00px 120.29KB.The crystal structure analysis allows us to propose a detailed mechanism for MST in which an Asp-His-Ser catalytic triad is positioned to activate the nucleophilic cysteine residue and participate in general acid-base chemistry, whereas our kinetic analysis indicates that thioredoxin is likely to be the major physiological persulfide acceptor for MST.ĭepartment of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600, USA. The crystal structure of MST reveals a mixture of the product complex containing pyruvate and an active site cysteine persulfide (Cys(248)-SSH) and a nonproductive intermediate in which 3-MP is covalently linked via a disulfide bond to an active site cysteine. The kinetics of H2S production by MST from 3-MP was studied at pH 7.4 in the presence of various physiological persulfide acceptors: cysteine, dihydrolipoic acid, glutathione, homocysteine, and thioredoxin, and in the presence of cyanide. In this study, we have expressed, purified, and crystallized human MST in the presence of the substrate 3-mercaptopyruvate (3-MP).
The contribution of MST versus the other two H2S generators, cystathionine β-synthase and γ-cystathionase, has been difficult to evaluate because many studies on MST have been conducted at high pH and have used varied reaction conditions. Mercaptopyruvate sulfurtransferase (MST) is a source of endogenous H2S, a gaseous signaling molecule implicated in a wide range of physiological processes. Biologically Interesting Molecule Reference Dictionary (BIRD).