thiaminepyrofosfaatafhankelijke

Thiamine pyrophosphate, often abbreviated as TPP, is the biologically active coenzyme form of thiamine, also known as vitamin B1. It plays a critical role in carbohydrate metabolism across virtually all living organisms. TPP is essential for the function of several key enzymes involved in energy production.

One of its most prominent roles is as a cofactor for pyruvate dehydrogenase, an enzyme complex that bridges glycolysis and the citric acid cycle by converting pyruvate into acetyl-CoA. TPP is also a required cofactor for alpha-ketoglutarate dehydrogenase, a crucial enzyme within the citric acid cycle itself, facilitating the conversion of alpha-ketoglutarate to succinyl-CoA.

Furthermore, TPP is indispensable for the activity of transketolase, an enzyme in the pentose phosphate pathway. This pathway is vital for generating NADPH, a reducing agent used in anabolic processes and in protecting cells from oxidative stress, and for producing precursor molecules for nucleotide biosynthesis.

Deficiency in thiamine, and consequently in TPP formation, can lead to severe health consequences. The most well-known condition associated with thiamine deficiency is beriberi, which can manifest in dry or wet forms, affecting the nervous system and cardiovascular system, respectively. Wernicke-Korsakoff syndrome, a neurological disorder often seen in individuals with chronic alcoholism due to impaired thiamine absorption and utilization, is another serious consequence of insufficient TPP.