STRUCTURAL ENERGETICS OF PROTEIN STABILITY AND FOLDING COOPERATIVITY
STRUCTURAL ENERGETICS OF PROTEIN STABILITY AND FOLDING COOPERATIVITY
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DOI：
10.1351/pac199365091939
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发表时间：
1993-09-01
影响因子：
1.8
通讯作者：
FREIRE, E
中科院分区：
文献类型：
--
作者：
MURPHY, KP;FREIRE, E
大量研究表明，球状蛋白的折叠/展开转变涉及折叠和展开状态之间的热力学稳定中间结构很少或不涉及。最近，我们开发了一种分层配分函数形式，旨在了解蛋白质热转变的协作性质。配分函数中的能量项与蛋白质的结构特性相关，即埋藏表面积和残基数量。以磷酸甘油酸激酶和肌红蛋白为例，结果表明，中间折叠状态因两个特征而不稳定：中间结构剩余折叠区域上的非极性表面积不利暴露，以及与剩余折叠区域相邻的多肽链部分的构型熵增益减少。
Numerous studies have demonstrated that the folding/unfolding transitions of globular proteins involve very few or no thermodynamically stable intermediate structures between the folded and unfolded states. Recently we have developed a hierarchical partition function formalism aimed at gaining an understanding of the cooperative nature of thermal transitions in proteins. The energetic terms in the partition function are correlated to structural properties of the protein, namely buried surface areas and number of residues. Using phosphoglycerate kinase and myoglobin as examples, it is shown that intermediately folded states are destabilized by two features: the unfavorable exposure of apolar surface area on regions of the intermediate structure remaining folded, and a decreased gain in configurational entropy for portions of the polypeptide chain which are adjacent to those regions remaining folded.