Amino acid sequences of neurotoxic protein variants from the venom of Centruroides sculpturatus Ewing.
Amino acid sequences of neurotoxic protein variants from the venom of Centruroides sculpturatus Ewing.
复制标题
来自雕刻刺猬尤因毒液的神经毒性蛋白变体的氨基酸序列。
DOI：
10.1016/0003-9861(74)90082-4
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发表时间：
1974
影响因子：
3.9
通讯作者：
R. Mlejnek
中科院分区：
文献类型：
--
作者：
Donald R. Babin;D. Watt;Susan M. Goos;R. Mlejnek
用CM-纤维素层析法将蝎子的毒液分成十个蛋白质区带。在醋酸铵显色剂中进一步纯化DEAE Sephadex上的三个区，产生了三种主要的神经毒素，分别命名为变异体1、2和3。变异体1和3分别由65个氨基酸残基组成，变异体2由66个残基组成，每个变异体是由四个二硫键交联的单一多肽链。这三个变异体在氨基末端有赖氨酸，在羧基末端有丝氨酸，它们的序列显示出高度的同源性。变异体2的完整结构是根据其胰凝乳多肽提供的序列和重叠部分推导出来的。测定了变异体1和变异体3的大部分胰蛋白酶多肽的序列，并与变异体2的同源多肽进行了比对。结果表明，变异体2和变异体3之间存在4个序列差异，变异体1和变异体2之间存在9个差异，变异体1和变异体3在其序列中的5个位置存在差异。三种蛋白质变体之间的这些差异存在于分子的氨基末端的三分之一，除了变体1和3的羧基末端的一个丝氨基残基的缺失。
The venom from the scorpion,Centruroides sculpturatusEwing (range, Southwestern United States), was fractionated into ten protein zones by chromatography on CM-cellulose. Further purification of three of these zones on DEAE Sephadex in ammonium acetate developers yielded three principal neurotoxins designated variants 1, 2, and 3. Variants 1 and 3 each consist of 65 amino acid residues, variant 2 is composed of 66 residues, and each variant is a single polypeptide chain crosslinked by four disulfide bridges. The three variants have lysine at the amino terminus, serine at the carboxyl terminus, and their sequences exhibit a high degree of homology. The complete structure of variant 2 was deduced from the sequence of its tryptic peptides and overlaps provided by its chymotryptic peptides. The sequences of most of the tryptic peptides of variants 1 and 3 were determined, and the peptides were aligned by comparison with the homologous peptides in variant 2. The results show that there are 4 differences in sequence between variants 2 and 3 and 9 differences between variants 1 and 2. Variants 1 and 3 differ from each other at 5 positions in their sequences. These differences between the three protein variants are found in the amino terminal one-third of the molecules except for the deletion of one seryl residue at the carboxyl terminal of variants 1 and 3.