Elucidation of d-allulose recognition mechanism in ketose 3-epimerase.

Autor: Watanabe M; Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan., Nakamichi Y; Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), 3-11-32 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan., Mine S; Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan. Electronic address: s-mine@aist.go.jp.
Jazyk: angličtina
Zdroj: Journal of bioscience and bioengineering [J Biosci Bioeng] 2024 Dec; Vol. 138 (6), pp. 488-494. Date of Electronic Publication: 2024 Sep 23.
DOI: 10.1016/j.jbiosc.2024.08.010
Abstrakt: d-Allulose is a low-calorie sweetener with multiple nutritional functions that can be produced through d-fructose isomerization by ketose 3-epimerase (KEase). l-Ribulose 3-epimerase from Arthrobacterglobiformis (AgLRE) is one of the most important enzymes that produce d-allulose; however, its substrate recognition mechanism is unknown. In this study, the crystal structures of AgLRE and its complex with d-allulose and d-fructose were determined. Upon substrate binding, the hydrophobic residues around the active-site entrance move toward the bound substrate. A comparison of AgLRE and other KEase structures revealed that the substrate-binding residues are not the main factors responsible for its marked specificity for d-allulose and d-fructose, but the hydrophobicity of the active site pocket influences substrate recognition. Particularly, the two hydrophobic regions at the active site entrance are the regulatory elements that modulate substrate recognition by AgLRE. This study provides useful information for designing AgLRE to increase its affinity for d-allulose and d-fructose.
(Copyright © 2024 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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