The mercaptopyruvate sulfurtransferase of Trichomonas vaginalis links cysteine catabolism to the production of thioredoxin persulfide.

ABSTRACT: Trichomonas vaginalis is a protozoan parasite of humans that is able to synthesize cysteine de novo using cysteine synthase but does not produce glutathione. In this study, high pressure liquid chromatography analysis confirmed that cysteine is the major intracellular redox buffer by showing that T. vaginalis contains high levels of cysteine ( approximately 600 mum) comprising more than 70% of the total thiols detected. To investigate possible mechanisms for the regulation of cysteine levels in T. vaginalis, we have characterized enzymes of the mercaptopyruvate pathway. This consists of an aspartate aminotransferase (TvAspAT1), which transaminates cysteine to form 3-mercaptopyruvate (3-MP), and mercaptopyruvate sulfurtransferase (TvMST), which transfers the sulfur of 3-MP to a nucleophilic

SUBMITTER: Westrop GD 

PROVIDER: S-EPMC2785193 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature