title: Structures of lactate dehydrogenase A (LDHA) in apo, ternary and inhibitor-bound forms.
abstract: Lactate dehydrogenase (LDH) is an essential metabolic enzyme that catalyzes the interconversion of pyruvate and lactate using NADH/NAD(+) as a co-substrate. Many cancer cells exhibit a glycolytic phenotype known as the Warburg effect, in which elevated LDH levels enhance the conversion of glucose to lactate, making LDH an attractive therapeutic target for oncology. Two known inhibitors of the human muscle LDH isoform, LDHA, designated 1 and 2, were selected, and their IC50 values were determined to be 14.4 ± 3.77 and 2.20 ± 0.15 µM, respectively. The X-ray crystal structures of LDHA in complex with each inhibitor were determined; both inhibitors bind to a site overlapping with the NADH-binding site. Further, an apo LDHA crystal structure solved in a new space group is reported, as well as a complex with both NADH and the substrate analogue oxalate bound in seven of the eight molecules and an oxalate only bound in the eighth molecule in the asymmetric unit. In this latter structure, a kanamycin molecule is located in the inhibitor-binding site, thereby blocking NADH binding. These structures provide insights into LDHA enzyme mechanism and inhibition and a framework for structure-assisted drug design that may contribute to new cancer therapies.
authors: Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 3Y6, Canada.
authors: Subramaniapillai
authors: S
authors: Kolappan
authors: Alectos Therapeutics Inc., 8999 Nelson Way, Burnaby, BC V5A 4B5, Canada.
authors: David L
authors: DL
authors: Shen
authors: Alectos Therapeutics Inc., 8999 Nelson Way, Burnaby, BC V5A 4B5, Canada.
authors: Renee
authors: R
authors: Mosi
authors: Alectos Therapeutics Inc., 8999 Nelson Way, Burnaby, BC V5A 4B5, Canada.
authors: Jianyu
authors: J
authors: Sun
authors: Alectos Therapeutics Inc., 8999 Nelson Way, Burnaby, BC V5A 4B5, Canada.
authors: Ernest J
authors: EJ
authors: McEachern
authors: Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 3Y6, Canada.
authors: David J
authors: DJ
authors: Vocadlo
authors: Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 3Y6, Canada.
authors: Lisa
authors: L
authors: Craig
mesh_terms: D001665:Binding Sites; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000378:metabolism; D000080864:Lactate Dehydrogenase 5; D062105:Molecular Docking Simulation; D009243:NAD / Q000378:metabolism; D009369:Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000378:metabolism; D019815:Oxalic Acid / Q000378:metabolism; D011487:Protein Conformation
chemical_list: D004791:Enzyme Inhibitors; D007527:Isoenzymes; D009243:NAD; D019815:Oxalic Acid; D007770:L-Lactate Dehydrogenase; D000080864:Lactate Dehydrogenase 5
keywords: LDHA; Warburg effect; cancer therapy; enzyme inhibition; glycolysis; lactate dehydrogenase A; oxalate; pyruvate