pH值和钙离子对尖吻蝮蛇抗血小板凝集素二级结构的影响(英文)  

Effects of pH Value and Ca^(2+) Ion on the Secondary Structure of Agkisacutacin from Agkistrodon Acutus Venom

作　　者：陈结霞[1] 徐小龙[1] 王守业[1] 张立云[1] 刘清亮[1] 

机构地区：[1]中国科学技术大学化学系,合肥230026

出　　处：《无机化学学报》2007年第5期849-853,共5页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金资助项目(No.20571069,20171041)。

摘　　要：尖吻蝮蛇毒中抗血小板凝集素是凝血因子IX/凝血因子X结合蛋白,它具有抗凝血和抑制血小板凝集双重活性。用红外光谱、拉曼光谱和CD谱研究了抗血小板凝集素的二级结构以及pH值和钙离子对其二级结构的影响。用CD谱测得,在水溶液中,抗血小板凝集素的主要骨架构象为β-折叠(26.3%)和α-螺旋(19.6%)结构。拉曼光谱显示,在粉末状态,其α-螺旋含量显著降低。CD谱还表明,抗血小板凝集素在pH值3.0￣11.0范围内保持稳定的天然结构,钙离子诱导的抗血小板凝集素结构变化是可逆的,钙离子在稳定抗血小板凝集素的天然结构中起重要作用。Agkisacutacin isolated from the venom of Agkistrodon acutus is a coagulation factor IX/coagulation factor X-binding protein with marked anticoagulant- and platelet-modulating activities. The effects of pH value and Ca^2＋ ion on the secondary structure of Agkisacutacin have been studied by FTIR, Raman and circular dichroism （CD） spectroscopy. The main backbone conformations of holo-Agkisacutacin are α-helix （19.6%） and β- sheet （26.3%） as determined by CD spectroscopy. According to the Raman measurements, the content of or-helix of holo-Agkisacutacin in solid powder is less than that in solution. The conformation of Agkisacutacin is stable in the pH range of 3.0-11.0 as shown by CD spectroscopy. Ca^2＋-induced conformation change of Agkisacutacin is reversible. Ca^2＋ ion plays an important role in the stabilization of the structure of Agkisacutacin.

关 键 词：抗血小板凝集素 二级结构 圆二色谱 拉曼光谱 红外光谱 

分 类 号：O614.2[理学—无机化学] O614.33[理学—化学]