NMR Research Today is a free monthly online journal that collates and summarizes the latest research about NMR, including details on nuclear magnetic resonance, structural determination, techniques.

Quantitative 13C and 2H NMR relaxation studies of the 723-residue enzyme malate synthase G reveal a dynamic binding interface.

Tugarinov V, Kay LE

Department of Medical Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8.

A detailed understanding of molecular recognition is predicated not only on high-resolution static structures of the free and bound states but also on information about how these structures change with time, that is, molecular dynamics. Here we present a deuterium ((2)H) and carbon ((13)C) NMR relaxation study of methyl side chain dynamics in the 82 kDa enzyme malate synthase G (MSG) that is a promising target for the development of new antibiotic agents. It is shown that excellent agreement between (2)H- and (13)C-derived measures of dynamics is obtained, with correlation coefficients exceeding 0.95. The binding interface formed by MSG and its substrates is found to be highly dynamic in the ligand-free state of the enzyme with rigidification upon binding substrate. This study establishes that detailed, quantitative information about methyl side chain dynamics can be obtained by NMR on proteins with molecular masses on the order of 100 kDa and opens up the possibilities for studies of motion in a large number of important systems.

Published 7 December 2005 in Biochemistry, 44(49): 15970-7.
Full-text of this article is available online (may require subscription).

© 2005-2008 NMR Research Today. All Rights Reserved.