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Ca 2+ dissociation from the C‐terminal EF‐hand pair in calmodulin: A steered molecular dynamics study
Author(s) -
Zhang Yong,
Tan Hongwei,
Lu Yanyan,
Jia Zongchao,
Chen Guangju
Publication year - 2008
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2008.03.010
Subject(s) - calmodulin , dissociation (chemistry) , chemistry , molecular dynamics , ef hand , biophysics , stereochemistry , calcium , crystallography , computational chemistry , biology , organic chemistry
We used steered molecular dynamics (SMD) to simulate the process of Ca 2+ dissociation from the EF‐hand motifs of the C‐terminal lobe of calmodulin. Based on an analysis of the pulling forces, the dissociation sequences and the structural changes, we show that the Ca 2+ ‐coordinating residues lose their binding to Ca 2+ in a stepwise fashion. The two Ca 2+ ions dissociate from the two EF‐hands simultaneously, with two distinct groups among the five Ca 2+ ‐coordinating residues affecting the EF‐hand conformational changes differently. These results provide new insights into the effects of Ca 2+ on calmodulin conformation, from which a novel sequential mechanism of Ca 2+ ‐calmodulin dissociation is proposed.