Thiamin nutrition and catalysis-induced instability of thiamin diphosphate.
Thiamin (vitamin B1) is required in animal diets because it is the precursor of the enzyme cofactor, thiamin diphosphate. Unlike other B vitamins, the dietary thiamin requirement is proportional to non-fat energy intake but there is no obvious biochemical reason for this relationship. In the present communication we show for two enzymes that the cofactor undergoes a slow destruction during catalysis, which may explain the interdependence of thiamin and energy intakes.
McCourt
Jennifer A
JA
School of Molecular and Microbial Sciences, University of Queensland, Brisbane, Queensland 4072, Australia.
Nixon
Peter F
PF
Duggleby
Ronald G
RG
D000095:Acetolactate Synthase / Q000737:chemistry; D000818:Animals; D002384:Catalysis; D003067:Coenzymes / Q000737:chemistry; D004734:Energy Metabolism; D004795:Enzyme Stability; D009751:Nutritional Requirements; D011767:Pyruvate Decarboxylase / Q000737:chemistry; D013831:Thiamine / Q000737:chemistry*; D013835:Thiamine Pyrophosphate / Q000737:chemistry
D003067:Coenzymes; D000095:Acetolactate Synthase; D011767:Pyruvate Decarboxylase; D013835:Thiamine Pyrophosphate; D013831:Thiamine