Residues in the fructose-binding pocket are required for ketohexokinase-A activity.

Autor:	Ferreira JC; Science Division, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates., Villanueva AJ; Science Division, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates., Fadl S; Science Division, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates., Al Adem K; Science Division, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates., Cinviz ZN; Graduate School of Engineering and Natural Sciences, Istanbul Medipol University, Istanbul, Turkey., Nedyalkova L; Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada., Cardoso THS; G42 Healthcare Omics Excellence Center, Abu Dhabi, United Arab Emirates., Andrade ME; Horticultural Sciences Department, University of Florida, Gainesville, Florida, USA., Saksena NK; Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia., Sensoy O; Graduate School of Engineering and Natural Sciences, Istanbul Medipol University, Istanbul, Turkey; Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey., Rabeh WM; Science Division, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates. Electronic address: wael.rabeh@nyu.edu.
Jazyk:	angličtina
Zdroj:	The Journal of biological chemistry [J Biol Chem] 2024 Aug; Vol. 300 (8), pp. 107538. Date of Electronic Publication: 2024 Jul 04.
DOI:	10.1016/j.jbc.2024.107538
Abstrakt:	Excessive fructose consumption is a primary contributor to the global surges in obesity, cancer, and metabolic syndrome. Fructolysis is not robustly regulated and is initiated by ketohexokinase (KHK). In this study, we determined the crystal structure of KHK-A, one of two human isozymes of KHK, in the apo-state at 1.85 Å resolution, and we investigated the roles of residues in the fructose-binding pocket by mutational analysis. Introducing alanine at D15, N42, or N45 inactivated KHK-A, whereas mutating R141 or K174 reduced activity and thermodynamic stability. Kinetic studies revealed that the R141A and K174A mutations reduced fructose affinity by 2- to 4-fold compared to WT KHK-A, without affecting ATP affinity. Molecular dynamics simulations provided mechanistic insights into the potential roles of the mutated residues in ligand coordination and the maintenance of an open state in one monomer and a closed state in the other. Protein-protein interactome analysis indicated distinct expression patterns and downregulation of partner proteins in different tumor tissues, warranting a reevaluation of KHK's role in cancer development and progression. The connections between different cancer genes and the KHK signaling pathway suggest that KHK is a potential target for preventing cancer metastasis. This study enhances our understanding of KHK-A's structure and function and offers valuable insights into potential targets for developing treatments for obesity, cancer, and metabolic syndrome. Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article. (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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