蛋白质及多肽的C端分析

本文采用（异）硫氰酸化学法，以乙酸酐为活化试剂，四丁铵硫氰酸为偶联试剂，溴甲基萘为烷化试剂，将蛋白质或多肽的Ｃ端依次转化并裂解为ＡＴＨ－氨基酸，在２５４ｎｍ进行检测。分析了若干种天然的、基因工程表达的蛋白质或多肽，测定了不同长度的Ｃ端序列，并确证了Ｃ端的修饰及突变情况。为蛋白质和多肽的完整性、均一性，基因工程产品及合成多肽的质控提供了重要的Ｃ端信息。目前，可在１￣２ｎｍｏｌ水平上测定了３￣５个Ｃ端

C terminal Analysis of Proteins and Peptides

A chemical method for C terminal sequencing has been used to analyze the C terminus of proteins and peptides, which can be converted to proteinyl alkylated thiohydantoin (proteinyl ATH) or peptidyl ATH via activated with acetic anhydride, coupled with and alkylated with bromomethylene. The C terminal ATH amino acid can be cleaved and detected at 254 nm. The C terminal sequences with varied lengths have been obtained from natural and recombinant proteins and peptides by the C terminal analysis, and modifications and mutations of C terminus have been found. By this method, important information on C terminus of proteins and peptides can be obtained for the identification of recombinant products and sythetic peptides. At presant, starting with samples of 1-2 nmole, C terminal of 3-5 residues or that of over 10 residues in some case, can be successfully determined.