Hoang Linh, Maity Haripada, Krishna Mallela M G, Lin Yan, Englander S Walter
Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6059, USA.
J Mol Biol. 2003 Aug 1;331(1):37-43. doi: 10.1016/s0022-2836(03)00698-3.
The alkaline transition of cytochrome c is a model for protein structural switching in which the normal heme ligand is replaced by another group. Stopped flow data following a jump to high pH detect two slow kinetic phases, suggesting two rate-limiting structure changes. Results described here indicate that these events are controlled by the same structural unfolding reactions that account for the first two steps in the reversible unfolding pathway of cytochrome c. These and other results show that the cooperative folding-unfolding behavior of protein foldons can account for a variety of functional activities in addition to determining folding pathways.
细胞色素c的碱性转变是蛋白质结构转换的一个模型，其中正常的血红素配体被另一个基团取代。跃升至高pH值后的停流数据检测到两个缓慢的动力学阶段，表明存在两个限速结构变化。此处描述的结果表明，这些事件受相同的结构解折叠反应控制，这些反应构成了细胞色素c可逆解折叠途径的前两个步骤。这些以及其他结果表明，蛋白质折叠子的协同折叠-解折叠行为除了决定折叠途径外，还能解释多种功能活性。
