Proteins in frozen solutions: Evidence of ice-induced partial unfolding
Proteins in frozen solutions: Evidence of ice-induced partial unfolding
复制标题
DOI：
10.1016/s0006-3495(96)79640-6
复制
发表时间：
1996-02-01
影响因子：
3.4
通讯作者：
Gabellieri, E
中科院分区：
文献类型：
--
作者：
Strambini, GB;Gabellieri, E
从埋在球状蛋白质的紧凑刚性核心中的色氨酸残基的磷光寿命急剧减少，可以证明水溶液的冷冻总是伴随着天然折叠的显著松动，这种改变需要相当大的二级和三级结构的损失。这种现象在冰融化时基本上是可逆的，尽管在某些情况下，一小部分大分子既不能恢复初始的磷光性质，也不能恢复催化活性。寿命参数的变化被认为是一个光滑的函数的剩余体积的液态水与冰平衡，并取决于冰的形态。加入甘油和蔗糖等冷冻保护剂可大大减弱甚至消除这种扰动。这些结果被解释在蛋白质分子吸附到冰的表面上。
From a drastic decrease in the phosphorescence lifetime of tryptophan residues buried in compact rigid cores of globular proteins, it was possible to demonstrate that freezing of aqueous solutions is invariably accompanied by a marked loosening of the native fold, an alteration that entails considerable loss of secondary and tertiary structure. The phenomenon is largely reversible on ice melting although,in some cases, a small fraction of macromolecules recovers neither the initial phosphorescence properties nor the catalytic activity. The variation in the lifetime parameter was found to be a smooth function of the residual volume of liquid water in equilibrium with ice and to depend on the morphology of ice. The addition of cryoprotectants such as glycerol and sucrose profoundly attenuates or even eliminates the perturbation. These results are interpreted in terms of adsorption of protein molecules onto the surface of ice.