β-Hydroxy β-methylglutaryl-CoA ( HMG-CoA ), also known as 3-hydroxy-3-methylglutaryl coenzyme A , is an intermediate in the mevalonate and ketogenesis pathways. It is formed from acetyl CoA and acetoacetyl CoA by HMG-CoA synthase . The research of Minor J. Coon and Bimal Kumar Bachhawat in the 1950s at University of Illinois led to its discovery.
6-437: HMG-CoA is a metabolic intermediate in the metabolism of the branched-chain amino acids , which include leucine , isoleucine , and valine . Its immediate precursors are β-methylglutaconyl-CoA (MG-CoA) and β-hydroxy β-methylbutyryl-CoA (HMB-CoA). HMG-CoA reductase catalyzes the conversion of HMG-CoA to mevalonic acid , a necessary step in the biosynthesis of cholesterol. Mevalonate synthesis begins with
12-463: A substrate into a product that serves as the substrate for the next reaction . Metabolic intermediates are compounds that form during these steps, and they are neither the starting substrate nor the final product of the pathway. These intermediates are crucial because they allow for regulation, energy storage, and extraction of chemical energy in a controlled manner. Metabolic intermediates can belong to different biochemical classes based on
18-452: Is the primary regulatory point in this pathway. Mevalonate serves as the precursor to isoprenoid groups that are incorporated into a wide variety of end-products, including cholesterol in humans. HMG-CoA lyase breaks it into acetyl CoA and acetoacetate . This biochemistry article is a stub . You can help Misplaced Pages by expanding it . Metabolic intermediate Metabolic intermediates are compounds produced during
24-432: The beta-ketothiolase -catalyzed Claisen condensation of two molecules of acetyl-CoA to produce acetoacetyl CoA . The following reaction involves the joining of acetyl-CoA and acetoacetyl-CoA to form HMG-CoA, a process catalyzed by HMG-CoA synthase . In the final step of mevalonate biosynthesis, HMG-CoA reductase , an NADPH -dependent oxidoreductase , catalyzes the conversion of HMG-CoA into mevalonate , which
30-461: The conversion of substrates (starting molecules) into final products in biochemical reactions within cells . Although these intermediates are of relatively minor direct importance to cellular function, they can play important roles in the allosteric regulation of enzymes , glycolysis , the citric acid cycle , and amino acid synthesis . Metabolic pathways consist of a series of enzymatically catalyzed reactions where each step transforms
36-420: The type of pathway they are involved in. Some examples include: Some can be useful in measuring rates of metabolic processes (for example, 3,4-dihydroxyphenylacetic acid or 3-aminoisobutyrate ). Because they can represent unnatural points of entry into natural metabolic pathways, some (such as AICA ribonucleotide ) are of interest to researchers in developing new therapies. This biochemistry article
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