两种蜘蛛多肽毒素的电喷雾电离质谱法序列分析

虎纹捕鸟蛛毒素-(HWTX-)和敬钊缨毛蛛毒素-(JZTX-)是两种蜘蛛多肽类神经毒素。它们的大部分氨基酸序列已由Edman降解法测出,但仍有部分序列由于某些原因未能确定。为了鉴定未知部分的序列,利用电喷雾电离-四极杆-飞行时间质谱(ESI-Qq-TOF-MS)对两种蜘蛛毒素的酶解产物进行分析,获得其酶解片段的一级(MS)和二级(MS/MS)图谱,在用软件和手工的方式对含有未知序列的肽段进行解析后,得到未知部分确切氨基酸序列。研究表明:利用质谱的从头测序(denovosequencing)方法获得HWTX-和JZTX-完整的氨基酸序列。该方法在蛋白质和多肽的结构分析和鉴定与传统方法相比具有高灵敏度和快速的优势,是对传统Edman化学降解法的一个很好的补充。

Sequence Analysis of Two Spider Peptide Toxins by Electrospray-Qq-Time-of-Flight Mass Spectrometry

Jingzhaotoxin VIII and Huwentoxin VI are two kinds of spider peptidetoxins. The most of amino acid sequences of the two peptidetoxins were determined by Edman degradation, with a few of uncertain sequences due to the ambiguous signals in Edman degradation. In order to identify the uncertain parts of the sequences, the two toxins were digested by trypsin and then analyzed by electrospray ionization Qq time of flight mass spectrometry (ESI Qq TOF MS). By interpreting the resulting MS and MS/MS spectra related to the uncertain sequences with analytical software and by hand, the amino acid sequences of uncertain parts were clearly identified. The research shows that we have got the whole sequences of HWTX I and JZTX VIII. Compared with contraditional methods, the de novo sequencing using mass spectrometry has particular advantages in peptide structure analysis and identification of proteins and peptides, and can be used as a good complement for Edman degradation.