虎纹捕鸟蛛毒素-Ⅰ突变体A1Y-HWTX-Ⅰ的固相合成和生物学活性测定

用芴甲氧羰基 (Fmoc)固相多肽合成的方法在自制自动蛋白质化学工作站上合成了用酪氨酸 (Y)替代虎纹捕鸟蛛毒素 - (HWTX- )第一位丙氨酸 (A1 )的突变体 A1 Y- HWTX- .合成的突变体用 Edman降解和电喷雾质谱法进行鉴定 .活性分析结果证明 ,合成的 A1 Y- HWTX- 在含有谷胱甘肽的缓冲体系中氧化折叠后显示出与天然 HWTX- 完全相同的生物学活性 ,提示 Y替代 HWTX- 的 A1后并不明显影响 HWTX- 的活性部位和空间构象 ;A1与 HWTX- 生物学活性无关 .此外 ,将 Y引入 HWTX- 分子有助于利用碘标记方法研究 HWTX- 的作用机制

Solid-phase Synthesis and Bioactivity Analysis of A1Y-HWTX-I :a Mutant of Huwentoxin- I

The solid phase chemical synthesis of A1Y HWTX Ⅰ, a mutant of neurotoxic peptide huwentoxin Ⅰ (HWTX Ⅰ), in which Tyr was substituted for the residue Alal of HWTX Ⅰ, was carried out using the Fmoc chemistry in the automatic working station for protein chemistry. The synthetic mutant was identified by Edman degradation and ESI (electrospray ionization) mass spectrometry. The biological activity analysis demonstrated that the synthetic A1Y HWTX Ⅰ, after oxidatively folding in glutathione containing buffer, exhibited the biological activity identical with that of the natural HWTX Ⅰ, indicating that the substitution of Tyr (Y) for the first amino acid Ala(A1) of HWTX Ⅰ had not resulted in great changes in the active site and the whole conformation of HWTX Ⅰ and A1 was not related to the biological activity of HWTX Ⅰ. The experiment also demonstrated that the introduction of Y into HWTX Ⅰ would contribute to the researches of the mechanism of HWTX Ⅰ.