Repository: Freie Universität Berlin, Math Department

Quantifying the Importance of Protein Conformation on Ligand Migration in Myoglobin

Plattner, N. and Meuwly, M. (2012) Quantifying the Importance of Protein Conformation on Ligand Migration in Myoglobin. Biophysical Journal, 102 (2). pp. 333-341. ISSN 00063495

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Official URL: http://dx.doi.org/10.1016/j.bpj.2011.10.058

Abstract

Myoglobin (Mb) is a model system for ligand binding and migration. The energy barriers (ΔG) for ligand migration in Mb have been studied in the past by experiment and theory and significant differences between different approaches were found. From experiment, it is known that Mb can assume a large number of conformational substates. In this work, these substates are investigated as a possible source of the differences in migration barriers. We show that the initial structure significantly affects the calculated ΔG for a particular transition and that fluctuations in barrier heights δΔG are of similar magnitude as the free energy barriers themselves. The sensitivity of ΔG to the initial structure is compared to other sources of errors. Different protein structures can affect the calculated ΔG by up to 4 kcal/mol, whereas differences between simple point charge models and more elaborate multipolar charge models for the CO-ligand are smaller by a factor of two. Analysis of the structural changes underlying the large effect of the conformational substate reveals the importance of coupling between protein and ligand motion for migration.

Item Type:Article
Subjects:Physical Sciences > Chemistry
ID Code:1251
Deposited By: BioComp Admin
Deposited On:19 Apr 2013 12:35
Last Modified:19 Apr 2013 12:35

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