Structural features of the cytochrome c molten globule revealed by fluorescence energy transfer kinetics
Structural features of the cytochrome c molten globule revealed by fluorescence energy transfer kinetics
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DOI：
10.1021/ja028141j
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发表时间：
2002-12-18
影响因子：
15
通讯作者：
Winkler, JR
中科院分区：
文献类型：
--
作者：
Lyubovitsky, JG;Gray, HB;Winkler, JR
蛋白质的非天然状态参与多种细胞过程，包括蛋白质跨膜易位和淀粉样原纤维的形成。报告多肽整体结构异质性的探针可以解决这些状态分类中的歧义。利用荧光能量转移动力学，我们发现添加的阴离子改变了酿酒酵母iso-1细胞色素重折叠过程中存在的紧凑和延伸多肽结构之间的平衡。具体来说，在高盐浓度 (≥700 mM) 下，所有多肽均紧凑，平均 C 端荧光团-血红素分离度非常接近天然蛋白 (25 Å)。
Nonnative states of proteins are involved in a variety of cellular processes, including translocation of proteins across membranes and formation of amyloid fibrils. Probes that report on the structural heterogeneity of a polypeptide ensemble could resolve ambiguities in the classification of these states. Employing fluorescence energy transfer kinetics, we have shown that added anions shift the equilibrium between the compact and extended polypeptide structures that are present during refolding ofSaccaromyces cerevisiaeiso-1 cytochromec. Specifically, at high salt concentrations (≥700 mM), all of the polypeptides are compact with a mean C-terminal fluorophore-heme separation quite close to that in the native protein (25 Å).