ZnCl2与氧化胰岛素B链结合位点和切割位点的质谱指认

摘要

The bonding interaction and hydrolytic cleavage of oxidized insulin B chain with ZnCl2 in molar ratios of 1:1 1:2 and 1:3 at pH value of 2.5 and 40 ℃ were investigated by electrospray ionization mass spectrometry and tandem mass spectrometry. The results show that the binding sites of Zn2+ with oxidized insulin B chain are Arg22 and imidazole groups of His5, His10, which leads to the selective cleavages of the peptide bonds at Asn3-Gln4, His5-Leu6, Gly8-Ser9 and Glu21-Arg22 of oxidized insulin B chain.%采用电喷雾质谱和串联质谱研究了氧化胰岛素B链与ZnCl2的键合作用并成功地确定了切割位点.质谱研究显示在pH值2.5及40℃条件下,Zn2+通过与氧化胰岛素B链的氨基酸侧链His5,His10和Arg22结合,选择性地水解了肽键Asn3-Gln4,His5-Leu6,Gly8-Ser9和Glu21-Arg22.