63 by: Gemma Muray Garcia
Student – Gemma Muray Garcia
Enzyme – PYRUVATE DEHYDROGENASE (PDH)
E.C number: 1.2.4.1
Where is enzyme found? The enzyme pyruvate dehydrogenase is found in the mitochondrial matrix of eukaryotic cells. In prokaryotes it is found on the cytoplasm. It is found as a part of an enzyme complex: the pyruvate dehydrogenase complex (PDC).
What does the enzyme do? Pyruvate dehydrogenase complex transforms the pyruvate into acetyl-CoA. It is essential for the cellular respiration. That is the function of the complex, yet if we focus on the function of the one enzyme, this is responsible for removing the carboxyl group of the pyruvate. Then, the remaining molecule attaches to TTP. TPP (Thiamine Pyrophosphate) is a Co-Enzyme of Pyruvate dehydrogenase. The molecule attached to TPP is called hydroxyl ethyl TPP. Pyruvate dehydrogenase is the first enzyme of the complex, E1. The other enzymes (E2 and E3) will oxidize the hydroxyl ethyl to acetic acid, and along co-enzymes such as Co-Enzyme A (CoA) they will generate Acetyl Co-A. It also releases CO2 and NADH, an energetic molecule.
Any other interesting facts or important information on your enzyme – It is interesting how it is part of a multi-enzyme complex. And each of the enzymes that compose the complex have very different roles, yet overall they accomplish the main function, which is to convert pyruvate to Acetyl-CoA. It is also interesting how the complex requires so many co-factors in this process. The co-enzymes are: TTP, lypoylisine, FAD, NAD+ and Co-enzyme A. This enzyme is important for the cellular respiration, since it produces Acetyl Co-A which is required
for Krebs Cycle.
References
1. Berg, J. M., J. A. Tymoczko, and L. Stryer. “The Citric Acid Cycle.” In Biochemistry, 6th ed. (New York, NY: W. H. Freeman and Company, 2007), 477-479.
2. “Pyruvate dehydrogenase complex.” Wikipedia. Acceced September 28, 2024. 2015. https://en.wikipedia.org/wiki/Pyruvate_dehydrogenase_complex.
3. Minsuh Seo, … Yong-Hwan Lee, in Cancer Drug “Design and Discovery (Second Edition), 2014
4. “Pyruvate dehydrogenase Complex”.Science Direct. Brought by Thompson Rivers University. From: Epilepsy Research, 2015. https://www.sciencedirect.com/topics/medicine-and-dentistry/pyruvate-dehydrogenasecomplex
5. “Pyruvate Dehydrogenase”.Science Direct. Brought by Thompson Rivers University. From: A Quick Guide to Metabolic Disease Testing Interpretation (Second Edition) , 2020. https://www.sciencedirect.com/topics/medicine-and-dentistry/pyruvate-dehydrogenase
6. “Oxidation of Pyruvate and the Citric Acid Cycle”.Openstax.Chapter7.3. https://openstax.org/books/biology/pages/7-3-oxidation-of-pyruvate-and-the-citric-acidcycle
