Nanosecond-Timescale Dynamics and Conformational Heterogeneity in Human GCK Regulation and Disease.

Autor:	Sternisha SM; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida., Whittington AC; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida; Department of Biological Science, Florida State University, Tallahassee, Florida., Martinez Fiesco JA; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida., Porter C; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida., McCray MM; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida., Logan T; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida; Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida., Olivieri C; Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota., Veglia G; Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota; Department of Chemistry, University of Minnesota, Minneapolis, Minnesota., Steinbach PJ; Center for Molecular Modeling, Center for Information Technology, National Institutes of Health, Bethesda, Maryland. Electronic address: peter.steinbach@nih.gov., Miller BG; Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida. Electronic address: bgmiller@fsu.edu.
Jazyk:	angličtina
Zdroj:	Biophysical journal [Biophys J] 2020 Mar 10; Vol. 118 (5), pp. 1109-1118. Date of Electronic Publication: 2020 Jan 14.
DOI:	10.1016/j.bpj.2019.12.036
Abstrakt:	Human glucokinase (GCK) is the prototypic example of an emerging class of proteins with allosteric-like behavior that originates from intrinsic polypeptide dynamics. High-resolution NMR investigations of GCK have elucidated millisecond-timescale dynamics underlying allostery. In contrast, faster motions have remained underexplored, hindering the development of a comprehensive model of cooperativity. Here, we map nanosecond-timescale dynamics and structural heterogeneity in GCK using a combination of unnatural amino acid incorporation, time-resolved fluorescence, and 19 F nuclear magnetic resonance spectroscopy. We find that a probe inserted within the enzyme's intrinsically disordered loop samples multiple conformations in the unliganded state. Glucose binding and disease-associated mutations that suppress cooperativity alter the number and/or relative population of these states. Together, the nanosecond kinetics characterized here and the millisecond motions known to be essential for cooperativity provide a dynamical framework with which we address the origins of cooperativity and the mechanism of activated, hyperinsulinemia-associated, noncooperative variants. (Copyright © 2020 Biophysical Society. All rights reserved.)
Databáze:	MEDLINE
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