Plaxco K W, Millett I S, Segel D J, Doniach S, Baker D
Department of Biochemistry, University of Washington, Seattle 98195, USA.
Nat Struct Biol. 1999 Jun;6(6):554-6. doi: 10.1038/9329.
We have directly characterized the extent of chain collapse early in the folding of protein L using time-resolved small angle X-ray scattering. We find that, immediately after the initiation of refolding, the protein exhibits dimensions indistinguishable from those observed under highly denaturing, equilibrium conditions and that this expanded initial state collapses with the same rate as that of the overall folding reaction. The observation that chain compaction need not significantly precede the rate-limiting step of folding demonstrates that rapid chain collapse is not an obligatory feature of protein folding reactions.
我们利用时间分辨小角X射线散射直接表征了蛋白质L折叠早期链塌陷的程度。我们发现，在重新折叠开始后，该蛋白质呈现出与在高度变性的平衡条件下观察到的尺寸无法区分的状态，并且这种扩展的初始状态以与整体折叠反应相同的速率塌陷。链压实不一定在折叠的限速步骤之前显著发生，这一观察结果表明快速链塌陷不是蛋白质折叠反应的必然特征。
