Structural studies of alpha-bungarotoxin. 3. Corrections in the primary sequence and X-ray structure and characterization of an isotoxic alpha-bungarotoxin.
Structural studies of alpha-bungarotoxin. 3. Corrections in the primary sequence and X-ray structure and characterization of an isotoxic alpha-bungarotoxin.
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α-金环蛇毒素的结构研究。
DOI：
10.1021/bi00408a018
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发表时间：
1988
期刊：
影响因子：
2.9
通讯作者：
Basus,VJ
中科院分区：
文献类型：
--
作者：
Kosen,PA;Finer-Moore,J;McCarthy,MP;Basus,VJ
1987年12月8日收到的修订版Mandalpt摘要：从二维/相关和二维核Overhauser效应核磁共振（NMR）光谱的组合使用中推导出的-银环蛇毒素的最合理的化学位移分配集合与残基8和12以及残基66和70之间的公认氨基酸序列相冲突[Basus，V. J.，Billeter，M.，爱你的河一、斯特劳德河M.，& Kuntz，I. D.（1988）生物化学（三篇论文中的第一篇）。此外，通过常规方法纯化的α-银环蛇毒素的NMR谱证明了约10%总蛋白水平的第二种物质。用Mono-S（阳离子）色谱法从银环蛇毒素中分离出次要组分。单-S-纯化的银环蛇毒素及其胰蛋白酶肽段的序列测定表明，银环蛇毒素的正确序列是Ser-Pro-Ile（9-11位）和Pro-His-Pro（67-69位）。银环蛇毒素[Love，R.一、& Stroud，R. M.（1986）Protein Eng.1，37]用新的序列数据进行改进。结构的改进主要发现于残基9-11。两个重叠的胰蛋白酶肽的序列分析证明，从银环蛇毒素不同的次要物种取代的丙氨酸在位置31的缬氨酸。这种新的毒素，α-银环蛇毒素（瓦尔′ 31），以与α-银环蛇毒素相当的亲和力结合乙酰胆碱受体。
Revised Manuscript Received December 8, 1987 abstract: The most plausible set of chemical shift assignments for-bungarotoxin as deduced from the combined use of two-dimensional/-correlated and two-dimensional nuclear Overhauser effect nuclear magnetic resonance(NMR) spectroscopy was in conflict with theaccepted amino acid sequence between residues 8 and 12 and residues 66 and 70 [Basus, V. J., Billeter, M., Love, R. A., Stroud, R. M., & Kuntz, I. D.(1988) Biochemistry (first paper of three in this issue)]. Furthermore, NMR spectra of a-bungarotoxin, purified by conventionalmethods, evidenced a second species at the level of approximately 10% total protein. The minor component was separated from-bungarotoxin by Mono-S (cationic) chromatography. Sequencing of Mono-S-purified-bungarotoxin and one of its tryptic peptides showed that the correct sequence for-bungarotoxin is Ser-Pro-Ile at positions 9-11 and Pro-His-Pro at positions 67-69. The electron density map of-bungarotoxin [Love, R. A., & Stroud, R. M.(1986) Protein Eng. 1, 37] was refined with the new sequence data. Improvements in the structure were found primarily for residues 9-11. Sequence analysis of two overlapping tryptic peptides proved that the minor species differed from-bungarotoxin by replacement of a valine for an alanine at position 31. This new toxin, a-bungarotoxin (Val ‘31), binds to the acetylcholine receptor with an affinity that is comparable to that of a-bungarotoxin.