61 by: Jake Fetalver
Student – Jake Fetalver
Enzyme: Pyruvate Dehydrogenase (EC 1.2.4.1)
When glucose has undergone glycolysis to synthesize pyruvate, it enters the mitochondrial matrix through the mitochondrial pyruvate carrier found between the inner mitochondrial
membrane and intermembrane space. This is where the pyruvate dehydrogenase complex catalyzes a reaction that involves pyruvate. The Pyruvate Dehydrogenase Complex comprises three catalytic enzymes and five co-enzymes that cooperate to convert pyruvate into acetyl-CoA that enters the TCA cycle to synthesize ATP. These enzymes are labeled as E1, E2, and E3: pyruvate dehydrogenase, dihydrolipoyl transacetylase, and dihydrolipoyl dehydrogenase. Also, these are accompanied by three co-enzymes: TPP, Co-enzyme A, and lipoic acids along with two co-factors such as FAD and NAD+. Once pyruvate is successfully converted into acetyl CoA after different processes that take place in this complex, it is transferred to the TCA cycle to be used as a substrate for the synthesis of ATP.
Some effects caused by a deficiency in the pyruvate dehydrogenase enzyme are the inability to make acetyl CoA, lactic acid in the brain, and neurodegeneration. Hence, it is critical for
the pyruvate dehydrogenase complex to successfully convert pyruvate to a substrate for the citric acid cycle (TCA).
References
Patel, Mulchand S., and Lioubov G. Korotchkina. “The biochemistry of the pyruvate dehydrogenase complex.” Biochemistry and Molecular Biology Education 31, no. 1 (2003): 5-15.
https://d1wqtxts1xzle7.cloudfront.net/52137133/pdf-libre.pdf?1489420029=&response-contentdisposition=inline%3B+filename%3DThe_biochemistry_of_the_pyruvate_dehydro.pdf&Expires=1729202955&Signature=RMUwkCiYb4mlKZuAgY0gtkigp6ay0sdlzxgtkwK8RGw28frW9NEL0N8~v1oo1GphYGANZoSbkXhNvlxr4Tbmho6XMUZ8Fch8DzlW1xgFXTlqnuOs9BEUL5CXL–8qqSMMSC4HV4ARfKFAtv8sBQ32ET1X4YdKLJ8m~cvrWH-an7-QJIc8senwuTk7MbTValj1f7X1naPK3mTnGAFnFLevV~mM0~SPxPv0ldXbJ5Cjxmqnj~MiuyxyVyDqwlCcfo7KEJtjjXEcXN17B3WgKvClcKRn4f7G7XZEA~Ry2tloGBDICW6gz~M7KdlVM3r8gqfwO4s0UyEgt124wsvafwg__&Key-Pair-Id=APKAJLOHF5GGSLRBV4ZA (accessed October 9, 2024)
Robert A. Harris, Melissa M. Bowker-Kinley, Boli Huang, Pengfei Wu, “Regulation of the activity of the pyruvate dehydrogenase complex”, Advances in Enzyme Regulation, Volume
42, 2002, Pages 249-259, ISSN 0065-2571, https://doi.org/10.1016/S0065-2571(01)00061-9. (accessed October 9, 2024 (https://www.sciencedirect.com/science/article/pii/S0065257101000619)
