前导序列工程

Pro-sequence Engineering

在传统的蛋白质工程中,为了改变酶的特性,常采用诱变等方法在蛋白酶结构域中引入突变。在前导序列调节蛋白折叠机制的基础上,文章介绍了一种新的蛋白质工程技术——"前导序列工程"。前导序列工程是指当前导序列发生突变时,同一种多肽链可以折叠成具有不同高级结构、稳定性或特异性改变的构型。前导序列工程不仅是研究蛋白质折叠机理的重要工具,更是创造新型蛋白酶的一种十分有前途的新技术。文章以枯草杆菌蛋白酶为例,介绍了前导序列工程的意义与应用。例如,枯草杆菌蛋白酶在突变前导序列作用下可以得到底物特异性改变的酶,并且可以提高自动处理效率。一个枯草杆菌蛋白酶同族的前导序列可以作为变性枯草杆菌蛋白酶折叠的分子内伴侣帮助其折叠。

Conventional protein engineering techniques have thus far employed mutagenesis in the protease domain to modify the enzymatic properties. This new approach, termed as＂pro-sequence engineering＂, refers to an identical polypeptide can fold into an altered conformation with different secondary structure, stability and specificities through a mutated pro-sequence, which is not only an important tool for studying the mechanism of protein folding, but also a promising technolique for creating unique proteases with various beneficial properties. The autoprocessing efficiency was improved by modifications in the pro-sequence of mutant subtilisins with altered substrate specificity. Further, the pro-sequence from a subtilisin homologue was found to chaperone the intramolecular folding of denatured subtilisin.