Hecht M H, Hehir K M, Nelson H C, Sturtevant J M, Sauer R T
J Cell Biochem. 1985;29(3):217-24. doi: 10.1002/jcb.240290306.
The thermal denaturations of five revertant lambda repressors containing single amino acid substitutions in their N-terminal domains have been studied by differential scanning calorimetry. Two substitutions slightly decrease stability, and the remaining three render the protein more stable than wild type. The Gly48----Asn and Gly48----Ser proteins are 4 degrees C more stable than wild type. These two substitutions replace an alpha helical residue, and in each case a poor helix forming residue, glycine, is replaced by a residue with a higher helical propensity. We also present data showing that one revertant, Tyr22----Phe, has reduced operator DNA binding affinity despite its enhanced stability.
通过差示扫描量热法研究了五个在其N端结构域含有单个氨基酸取代的λ阻遏物回复突变体的热变性。两个取代稍微降低了稳定性，其余三个使蛋白质比野生型更稳定。Gly48→Asn和Gly48→Ser蛋白比野生型稳定4℃。这两个取代取代了一个α螺旋残基，并且在每种情况下，一个形成螺旋能力差的残基甘氨酸被一个具有更高螺旋倾向的残基所取代。我们还提供数据表明，一个回复突变体Tyr22→Phe，尽管其稳定性增强，但具有降低的操纵基因DNA结合亲和力。
