[26] Transition-state analogs of thiamine pyrophosphate

摘要: Publisher Summary This chapter describes the transition-state analogs of thiamine pyrophosphate. The major structural transformations that occur during catalysis most pyrophosphate-dependent enzymic reactions are presented in chapter. Common to all mechanisms high-energy intermediates which thiazole ring, unlike pyrophosphate itself, is uncharged. Both thiazolone (I) (TTPP) and thiothiazolone (II) (TTTPP), have been shown behave as for Escherichia coli pyruvate dehydrogenase, structures resemble these postulated but specifically metastable enamine (III) immediate product decarboxylation pyruvate. binding E. dehydrogenase complex so tight compounds inhibit stoichiometrically almost irreversibly at very low concentrations. Thiamine can be obtained by allowing react with pyrophosphoyl tetrachloride subsequently phosphoryiating resulting monophosphate crystalline phosphoric acid.