What is "thiamine pyrophosphate"

n. a coenzyme important in respiration in the Krebs cycle [syn: cocarboxylase]

Thiamine pyrophosphate (TPP or ThPP), or thiamine diphosphate (ThDP), or cocarboxylase is a thiamine (vitamin B) derivative which is produced by the enzyme thiamine diphosphokinase. Thiamine pyrophosphate is a cofactor that is present in all living systems, in which it catalyzes several biochemical reactions. It was first discovered as an essential nutrient ( vitamin) in humans through its link with the peripheral nervous system disease Beriberi, which results from a deficiency of thiamine in the diet.

TPP works as a coenzyme in many enzymatic reactions, such as:

• Pyruvate dehydrogenase complex
• Pyruvate decarboxylase in ethanol fermentation
• Alpha-ketoglutarate dehydrogenase complex
• Branched-chain amino acid dehydrogenase complex
• 2-hydroxyphytanoyl-CoA lyase
• Transketolase