Otzen D E, Fersht A R
MRC Unit for Protein Function & Design, Cambridge IRC for Protein Engineering, University Chemical Laboratory, UK.
Protein Eng. 1999 Jan;12(1):41-5. doi: 10.1093/protein/12.1.41.
Site-directed mutagenesis, including double-mutant cycles, is used routinely for studying protein-protein interactions. We now present a case analysis of chymotrypsin inhibitor 2 (CI2) and subtilisin BPN' using (i) a residue in CI2 that is known to interact directly with subtilisin (Tyr42) and (ii) two CI2 residues that do not have direct contacts with subtilisin (Arg46 and Arg48). We find that there are similar changes in binding energy on mutation of these two sets of residues. It can thus be difficult to interpret mutagenesis data in the absence of structural information.
定点诱变，包括双突变循环，常用于研究蛋白质-蛋白质相互作用。我们现在展示一个关于胰凝乳蛋白酶抑制剂2（CI2）和枯草杆菌蛋白酶BPN'的案例分析，使用（i）CI2中已知与枯草杆菌蛋白酶直接相互作用的一个残基（Tyr42），以及（ii）与枯草杆菌蛋白酶没有直接接触的两个CI2残基（Arg46和Arg48）。我们发现，这两组残基发生突变时，结合能有相似的变化。因此，在缺乏结构信息的情况下，很难解释诱变数据。
