Thiamine pyrophosphate

• Thiamine diphosphate
• Cocarboxylase

White solid

240-244 ° C ( decomposition)

Well in water (220 g · l-1 at 20 ° C)

Template: Infobox chemical / molecular formula search available

Thiamine pyrophosphate (TPP), and thiamine diphosphate (TDP ) is a phosphate ester of thiamine (vitamin B1). TPP is the coenzyme form of thiamine, and dominant in the cells of eukaryotes against the thiamine, because it will soon be synthesized from the latter by the enzyme Thiaminpyrophosphokinase.

The previously held view that TPP is not transported out of the cell, is wrong. It is known, at least one transport protein that is able to transport in mammals TPP.

Properties

Thiamine pyrophosphate crystallized in two hydrated forms. Both forms, a tetrahydrate and a 4.5 hydrate form triclinic crystal lattice with space group P1.

Function

Several TPP -dependent enzymes are located at important control points of cellular metabolism. General TPP interacts with aldehyde - transfer reactions. TPP is the prosthetic group of transketolase, an enzyme of the pentose phosphate pathway. Their activity in the red blood cells is a criterion for the assessment of the supply state with thiamine.

Other enzymes which TPP acts as a coenzyme:

• Pyruvate dehydrogenase (oxidative decarboxylation of pyruvate )
• α -ketoglutarate dehydrogenase ( TCA cycle )
• Branched-chain α -keto acid dehydrogenase ( breakdown of amino acids with branched side chains)
• Acetolactate synthase (2,3- Butandiolgärung )
• Pyruvate decarboxylase (alcoholic fermentation)
• Pyruvate
• Indolpyruvatdecarboxylase