Berendes R, Voges D, Demange P, Huber R, Burger A
Max-Planck-Institut für Biochemie, Martinsried, Germany.
Science. 1993 Oct 15;262(5132):427-30. doi: 10.1126/science.7692599.
Electrophysiology and structural studies were performed on an annexin V variant containing a mutation of glutamic acid-95 to serine in the center of the pore region. The mutation resulted in a lower single channel conductance for calcium and a strongly increased conductance for sodium and potassium, indicating that glutamic acid-95 is a crucial constituent of the ion selectivity filter. There were only minor differences in the crystal structures of mutant and wild-type annexin V around the mutation site; however, the mutant showed structural differences elsewhere, including the presence of a calcium binding site in domain III unrelated to the mutation. Analysis of the membrane-bound form of annexin V by electron microscopy revealed no differences between the wild type and mutant.
对孔区域中心谷氨酸-95突变为丝氨酸的膜联蛋白V变体进行了电生理学和结构研究。该突变导致钙的单通道电导降低，而钠和钾的电导大幅增加，表明谷氨酸-95是离子选择性过滤器的关键组成部分。突变体和野生型膜联蛋白V在突变位点周围的晶体结构只有微小差异；然而，突变体在其他地方表现出结构差异，包括结构域III中存在一个与突变无关的钙结合位点。通过电子显微镜对膜联蛋白V的膜结合形式进行分析，结果显示野生型和突变体之间没有差异。
