Researchers from National Autonomous University, Medical Department report details of new studies and findings in the area of taeniasis
2009 JUL 27 - (NewsRx.com) -- "Malate dehydrogenase (l-malate: NAD oxidoreductase, EC 1.1.1.37) from the cytoplasm of Taenia solium cysticerci (cMDHTs) was purified 48-fold through a four-step procedure involving salt fractionation, ionic exchange, and dye affinity chromatography. cMDHTs had a native M (r) of 64,000, while the corresponding value per subunit, obtained under denaturing conditions, was 32,000. The enzyme is partially positive, with an isoelectric point of 8.7, and had a specific activity of 2,615 U mg(-1) in the reduction of oxaloacetate," scientists in Mexico report. "The second to the 21st amino acids from cMDHTs N-terminal group were P G P L R V L I T G A A G Q I A Y N L S. This sequence is 100% identical to that of Echinococcus granulosus. Basic kinetic parameters were determined for this enzyme. The optimum pH for enzyme reaction was at 7.6 for oxaloacetate reduction and at 9.6 for malate oxidation. K (m) values for oxaloacetate, malate, NAD, and NADH were 2.4, 215, 50, and 48 A mc M, respectively. V (max) values for the substrates and cosubstrates as described above were 1,490, 87.8, 104, and 1,714 A mu mol min(-1) mg(-1). Several NAD analogs, structurally altered in either the pyridine or purine moiety, were observed to function as coenzymes in the reaction catalyzed by the purified malate dehydrogenase. cMDHTs activity was uncompetitive inhibited by arsenate for both the forward (Ki = 8.2 mM) and reverse (Ki = 77 mM) reactions. The mechanism of the cMDHTs reactivity was investigated kinetically by the product inhibition approach," wrote A. Plancarte and colleagues, National Autonomous University, Medical Department. The researchers concluded: "The results of this study are qualitatively consistent with an Ordered Bi Bi reaction mechanism, in which only the coenzymes can react with the free enzyme.." Plancarte and colleagues published their study in Parasitology Research (Purification, properties, and kinetic studies of cytoplasmic malate dehydrogenase from Taenia solium cysticerci. Parasitology Research, 2009;105(1):175-183). For more information, contact A. Plancarte, National Autonomous University of Mexico, Faculty Medical, Dept. of Microbiology & Parasitology, Mexico City 04510, DF, Mexico. Publisher contact information for the journal Parasitology Research is: Springer, 233 Spring St., New York, NY 10013, USA. Keywords: Mexico, Amino Acids, Chromatography, Dehydrogenase, Drugs, Enzyme Research, Oxidoreductase, Parasitology, Pharmaceuticals, Taeniasis, Therapy, Treatment, National Autonomous University, Medical Department. This article was prepared by Biotech Business Week editors from staff and other reports. Copyright 2009, Biotech Business Week via NewsRx.com.
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