A model of dynamic side-chain--side-chain interactions in the alpha-lactalbumin molten globule.
A model of dynamic side-chain--side-chain interactions in the alpha-lactalbumin molten globule.
复制标题
α-乳清蛋白熔球中动态侧链-侧链相互作用的模型。
DOI：
10.1110/ps.34101
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Peng,ZY
中科院分区：
文献类型：
--
作者：
Bai,P;Song,J;Luo,L;Peng,ZY
处于熔融球状态的蛋白质包含高水平的二级结构，以及基本的、天然的三级拓扑结构。因此，熔融球和天然蛋白质之间的结构相似性可能对理解蛋白质折叠问题具有重要意义。为了探索α-乳清蛋白（α-LA）熔融球中侧链-侧链相互作用的性质，我们确定了14种双突变蛋白中28-111二硫键形成的有效浓度，每种蛋白含有两个被丙氨酸取代的疏水核心残基。我们使用双突变体循环分析的框架将我们的结果与单丙氨酸取代的结果进行了比较，发现在大多数情况下，两个丙氨酸取代的影响是加性的。基于这些结果，我们提出了α-LA熔融球中侧链-侧链相互作用的模型，该模型考虑了这种部分折叠物种的动态性质。
Proteins in the molten globule state contain high levels of secondary structure, as well as a rudimentary, nativelike tertiary topology. Thus, the structural similarity between the molten globule and native proteins may have a significant bearing in understanding the protein‐folding problem. To explore the nature of side‐chain–side‐chain interactions in the α‐lactalbumin (α‐LA) molten globule, we determined the effective concentration for formation of the 28–111 disulfide bond in 14 double‐mutant proteins, each containing two hydrophobic core residues replaced by alanine. We compared our results with those of single‐alanine substitutions using the framework of double‐mutant cycle analysis and found that, in the majority of cases, the effects of two alanine substitutions are additive. Based on these results, we propose a model of side‐chain–side‐chain interactions in the α‐LA molten globule, which takes into consideration the dynamic nature of this partially folded species.