Conformational relaxations of urea- and guanidine hydrochloride-unfolded ferricytochrome c.
Conformational relaxations of urea- and guanidine hydrochloride-unfolded ferricytochrome c.
复制标题
尿素和盐酸胍未折叠的铁细胞色素 c 的构象松弛。
DOI：
10.1016/s0021-9258(17)38308-4
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发表时间：
1977
期刊：
影响因子：
--
通讯作者：
T. Tsong
中科院分区：
文献类型：
--
作者：
T. Tsong
蛋白质的几个最新研究未折叠蛋白质。在尿素和盐酸胍-未折叠的铁细胞色素c（马心），酸诱导的自旋状态的血红素基团的转换已被检测到的血红素的反式，色氨酸-59荧光，和蛋白质的特性粘度。通过温度跃变和停流方法，这第二次构象转变的动力学是复杂的。一个快速反应（tau 1），pH值无关，发生在50 μ s范围内;第二个反应（tau 2），在1 ms范围内，线性依赖于pH值，在碱性侧更快;第三个反应（tau 3），在1 s范围内，在pH值5.1时显示出S形转变，在酸性侧更快。结果是一致的动力学方案，其中涉及蛋白质的构象变化的血红素配位状态的转换。的动力学，沿着与以前的平衡研究，表明蛋白质分子内的配体或电荷相互作用，即使在强烈的变性条件下，如在高浓度的尿素和盐酸胍，不完全禁止。因此，与这些相互作用相关的肽链的局部结构可以存在于未折叠的蛋白质中。
Several recent studies of protein the unfolded proteins. In urea- and guanidine HCl-unfolded ferricytochrome c (horse heart), an acid-induced spin state transformation of the heme group has been detected by the heme absorptions, Trp-59 fluorescence, and the intrinsic viscosity of protein. Kinetics of this second conformational transition, by the temperature jump and stopped flow methods, are complex. One rapid reaction (tau1), pH-independent, occurs in a 50-mus range; the second reaction (tau2), in a 1-ms range, depends linearly upon pH and is faster at the alkaline side; a third reaction (tau3), in a 1-s range, shows a sigmoidal transition at pH 5.1 and is faster at the acidic side. The results are consistent with a kinetic scheme which involves protein conformational changes in the transformation of the heme coordination state. The kinetics, along with previous equilibrium studies, indicate that ligand or charge interactions within a protein molecule are not completely prohibited even in strongly denaturing conditions, such as in high concentrations of urea and guanidine HCl. Thus, local structures of peptide chain associated with these interactions can exist in the unfolded protein.