TY - JOUR T1 - The Effect of Macromolecular Crowding, Ionic Strength and Calcium Binding on Calmodulin Dynamics A1 - Wang, Qian A1 - Liang, Kao-Chen A1 - Czader, Arkadiusz A1 - Waxham, M. Neal A1 - Cheung, Margaret S. Y1 - 2011/07/28 N2 - Author Summary Proteins are workhorses for driving biological functions inside cells. Calmodulin (CaM) is a protein that can carry cellular signals by triggered conformational changes due to calcium binding that alters target binding. Interestingly, CaM is able to bind over 300 targets. One of the challenges in characterizing CaM's ability to bind multiple targets lies in that CaM is a flexible protein and its structure is easily modulated by the physicochemical changes in its surroundings, particularly inside a complex cellular milieu. In order to determine structure-function relationships of CaM, we employed a combined approach of experiments, computer simulations and statistical physics in the investigation of the effect of calcium-binding, salt concentration, and macromolecular crowding on CaM. The results revealed unique folding energy landscapes of CaM in the absence and presence of calcium ions and the structural implications of CaM are interpreted under cell-like conditions. Further, a large conformational change in CaM in response to environmental impacts, dictates the packing of local helices that may be critical to its function of target binding and recognition among vast target selections. JF - PLOS Computational Biology JA - PLOS Computational Biology VL - 7 IS - 7 UR - https://doi.org/10.1371/journal.pcbi.1002114 SP - e1002114 EP - PB - Public Library of Science M3 - doi:10.1371/journal.pcbi.1002114 ER -