PICOSECOND FLUORESCENCE DECAY OF LENS PROTEIN-GAMMA-II CRYSTALLIN
PICOSECOND FLUORESCENCE DECAY OF LENS PROTEIN-GAMMA-II CRYSTALLIN
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DOI：
10.1016/0301-4622(93)80045-k
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发表时间：
1993-10-01
影响因子：
3.8
通讯作者：
YOSHIHARA, K
中科院分区：
文献类型：
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作者：
BORKMAN, RF;DOUHAL, A;YOSHIHARA, K
测定了牛晶状体蛋白GAMA-II晶体蛋白中色氨酸残基在缓冲溶液中的荧光衰减。得到了发射波长、温度、溶解氧和变性溶剂的函数。该蛋白质呈现复杂的荧光衰减，符合长组分(Ns)和短组分(几百ps)的双指数模型。测量的伽马-II晶体的荧光量子产额数据允许计算辐射和非辐射速率常数。辐射速率常数与在其他吲哚类化合物中观察到的速率常数一致，而非辐射速率常数很大，这是伽马-II的短寿命的原因。伽马-II晶体蛋白的非辐射衰变与温度的依赖关系产生了只有1-2千卡/摩尔的小活化能，而参比化合物NAA的激活能为4千卡/摩尔，其势垒已知来自旋转异构体模型。
The fluorescence decay of tryptophan residues in the bovine lens protein gamma-II crystallin has been measured in aqueous buffer solutions. Results were obtained as a function of emission wavelength, temperature, dissolved oxygen, and denaturing solvent. The protein displayed complex fluorescence decay which fit a biexponential model with a long component (ns) and a short component (few hundred ps). Measured fluorescence quantum yields data for gamma-II crystallin allowed calculation of radiative and non-radiative rate constants. The radiative rate constant was consistent with that observed in other indole derivatives, while the nonradiative rate constant was quite large and accounted for the short lifetime in gamma-II. The temperature dependence of the non-radiative decay in gamma-II crystallin yielded a small activation energy of only 1-2 kcal/mol, compared to 4 kcal/mol for the reference compound NATA whose barrier is known to derive from the rotamer model.