Replacement of staphylococcal nuclease hydrophobic core residues with those from thermophilic homologues indicates packing is improved in some thermostable proteins
Replacement of staphylococcal nuclease hydrophobic core residues with those from thermophilic homologues indicates packing is improved in some thermostable proteins
复制标题
DOI：
10.1016/j.jmb.2004.09.008
复制
发表时间：
2004-11-12
影响因子：
5.6
通讯作者：
Stites, WE
中科院分区：
文献类型：
--
作者：
Chen, JM;Stites, WE
在嗜热生物中发现的蛋白质的稳定性紧密的疏水核心包装的重要性一直有激烈的争议。在这里，在三个嗜热同源物中发现的核心部分被移植到葡萄球菌核酸酶的核心中，葡萄球菌核酸酶是一种稳定性适中的蛋白质。通过比较三种突变体与先前在葡萄球菌核酸酶中这些相同位点建立的综合突变体文库的相互作用能来评价核心的包装。结果发现，一个嗜热序列的相互作用能是非常有利的和其他两个移植的嗜热序列的相互作用能是好的，与基于嗜温同源物中发现的核心的突变核心的相互作用能相当。正如预期的那样，当仅转移核心序列的一部分时，突变体蛋白相对于野生型葡萄球菌核酸酶总体上不稳定。总的结论是，包装相互作用的改善是一种机制，赋予稳定性，在一些蛋白质从嗜热菌，但不是所有。(C)2004 Elsevier Ltd.保留所有权利。
The importance of tight hydrophobic core packing in stabilizing proteins found in thermophilic organisms has been vigorously disputed. Here, portions of the cores found in three thermophilic homologues were transplanted into the core of staphylococcal nuclease, a protein of modest stability. Packing of the core was evaluated by comparing interaction energy of the three mutants to the comprehensive mutant library built up previously at these same sites in staphylococcal nuclease. It was found that the interaction energy of one thermophilic sequence is extraordinarily favorable and the interaction energies of other two transplanted thermophilic sequences are good, comparable to the interaction energies of mutant cores based on cores found in mesophilic homologues. As expected when transferring just a portion of the core sequence, the mutant proteins were destabilized overall relative to wild-type staphylococcal nuclease. The overall conclusion is that improvement of packing interactions is a mechanism to confer stability employed in some proteins from thermophiles, but not all. (C) 2004 Elsevier Ltd. All rights reserved.