Jardón-Valadez Eduardo, Bondar Ana-Nicoleta, Tobias Douglas J
Departamento de Recursos de la Tierra, Universidad Autónoma Metropolitana-Lerma, Lerma de Villada, Estado de México 52005, México.
Theoretical Molecular Biophysics Department of Physics, Freie University Arnimallee 14, Berlin 14195, Germany.
Biochim Biophys Acta. 2014 Dec;1837(12):1964-1972. doi: 10.1016/j.bbabio.2014.09.006.
Translocation of negatively charged ions across cell membranes by ion pumps raises the question as to how protein interactions control the location and dynamics of the ion. Here we address this question by performing extensive molecular dynamics simulations of wild type and mutant halorhodopsin, a seven-helical transmembrane protein that translocates chloride ions upon light absorption. We find that inter-helical hydrogen bonds mediated by a key arginine group largely govern the dynamics of the protein and water groups coordinating the chloride ion.
离子泵使带负电荷的离子跨细胞膜转运，这就引发了一个问题：蛋白质相互作用是如何控制离子的位置和动态变化的。在这里，我们通过对野生型和突变型嗜盐菌视紫红质进行广泛的分子动力学模拟来解决这个问题，嗜盐菌视紫红质是一种七螺旋跨膜蛋白，在吸收光时能转运氯离子。我们发现，由一个关键精氨酸基团介导的螺旋间氢键在很大程度上支配着蛋白质以及与氯离子配位的水分子基团的动态变化。
