东亚马氏钳蝎哺乳动物类神经毒素III的快原子轰击酶谱分析

应用快原子轰击酶谱分析检验了东亚马氏钳蝎哺乳动物类神经毒素III的氨基酸序列,对前人用Edman降解法测定的序列作了两处修正:(1)第60位氨基酸残基是脯氨酸而不是色氨酸;(2)C-端氨基酸是组氨酸而不是甘氨酸。分别用羧肽酶B降解和部分胰蛋白酶酶解后的质谱数据进一步证实了以上的修正。在分析中采用了化学修饰方法以减少表面抑制效应,从而得到完整的快原子轰击酶谱。

FAB mapping of Buthus marttensii Karch III

A mammal neurotoxin was isolated from the Buthus marttensii Karch with chromatography. Its Edman degradation-derived sequence was verified by FAB mapping of the tryptic digest of the sample. The results reveal that the sixtieth residue is proline instead of tryptophan and that the C-terminal residue is histidine without glycine. The revised sequence is further confirmed by comparing above FAB map with that of those peptides produced after further step of carboxypeptidase B digestion. FAB mapping of the partial tryptic digest also supports the correction. Chemical modification was applied to minimize the problem of surface suppression.