Effects of guanidine hydrochloride on the refolding kinetics of denatured thioredoxin.
Effects of guanidine hydrochloride on the refolding kinetics of denatured thioredoxin.
复制标题
盐酸胍对变性硫氧还蛋白重折叠动力学的影响。
DOI：
10.1021/bi00351a033
复制
发表时间：
1986
期刊：
影响因子：
2.9
通讯作者：
Stellwagen,E
中科院分区：
文献类型：
--
作者：
Kelley,RF;Wilson,J;Bryant,C;Stellwagen,E
ResultsEquilibrium测量。硫氧还蛋白中两个色氨酸残基的荧光发射强度随Gdn-HCl浓度的变化关系如图1所示。这种依赖性可分为三个区域：0至2 M Gdn-HCl之间的原生基线区，2至3 M Gdn-HCl之间的过渡区。在变性基线区观察到的强度依赖性与模型色氨酸残基等摩尔浓度时观察到的强度依赖性相当（Kelley & Stellwagen,(1984)）。在天然基线区观察到的荧光强度依赖性减弱可能反映了天然构象中部分猝灭的色氨酸残基的依赖性。如先前报道的，过渡区的中点在2.5 M Gdn-HCl处（Kelley & Stellwagen, 1984）。单次混合动力学测量。选取硫氧还蛋白在3 M Gdn-HCl中展开和变性硫氧还蛋白在2 M Gdn-HCl中再折叠的动力学曲线作为每一种构象变化的代表。
ResultsEquilibrium Measurements. The dependence of the fluorescence emission intensity of the two tryptophan residues in thioredoxin on Gdn-HCl concentration is shown in Figure 1. This dependence may be dividedinto three zones: the native base-line zone between zero and 2 M Gdn-HCl, the transition zone between 2 and 3 M Gdn-HCl. The intensity dependence observed in the denatured base-line zone is equivalent to that observed for an equimolar concentration of a model tryptophan residue (Kelley & Stellwagen,(1984). The diminished fluorescence intensity dependence observed in the native base-line zone presumably reflects that of the partially quenched tryptophan residues in the native conformation. The midpoint of the transition zone occurs at 2.5 M Gdn-HCl as reported previously (Kelley & Stellwagen, 1984). Single Mixing Kinetic Measurements. The kinetic profiles observed for the unfolding of thioredoxin in 3 M Gdn-HCl and the refolding of denatured thioredoxin in 2 M Gdn-HCl were selected as representative of each conformational change.