Ohage E C, Graml W, Walter M M, Steinbacher S, Steipe B
Genzentrum der Ludwig-Maximilians-Universität, München, Germany.
Protein Sci. 1997 Jan;6(1):233-41. doi: 10.1002/pro.5560060125.
The thermodynamic stability of a protein provides an experimental metric for the relationship of protein sequence and native structure. We have investigated an approach based on an analysis of the structural database for stability engineering of an immunoglobulin variable domain. The most frequently occurring residues in specific positions of beta-turn motifs were predicted to increase the folding stability of mutants that were constructed by site-directed mutagenesis. Even in positions in which different residues are conserved in immunoglobulin sequences, the predictions were confirmed. Frequently, mutants with increased beta-turn propensities display increased folding cooperativities, suggesting pronounced effects on the unfolded state independent of the expected effect on conformational entropy. We conclude that structural motifs with predominantly local interactions can serve as templates with which patterns of sequence preferences can be extracted from the database of protein structures. Such preferences can predict the stability effects of mutations for protein engineering and design.
蛋白质的热力学稳定性为蛋白质序列与天然结构之间的关系提供了一种实验度量。我们研究了一种基于免疫球蛋白可变结构域稳定性工程的结构数据库分析方法。预测β-转角基序特定位置上最常见的残基会增加通过定点诱变构建的突变体的折叠稳定性。即使在免疫球蛋白序列中不同残基保守的位置，这些预测也得到了证实。通常，具有增加的β-转角倾向的突变体表现出增加的折叠协同性，这表明对未折叠状态有显著影响，而与对构象熵的预期影响无关。我们得出结论，主要具有局部相互作用的结构基序可以作为模板，从中可以从蛋白质结构数据库中提取序列偏好模式。这种偏好可以预测蛋白质工程和设计中突变的稳定性效应。
