Flash photolysis of enzymes.
Flash photolysis of enzymes.
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酶的闪光光解。
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
J. F. Baugher
中科院分区：
文献类型：
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作者：
L. Grossweiner;A. G. Kaluskar;J. F. Baugher
芳香族残基的光电离构成了在γ大于250 nm处的蛋白质闪光光解中的主要初始光化学反应。已观察到的喷射电子作为eaq-和二硫化物桥电子加合物，也必须在身份不明的网站被捕获。在5微秒延迟下光电离的双羟酰（或酪氨酰）残基的数量约等于暴露的残基的数量。根据微观结构和关于永久性改变和残留物特异性的现有资料，通过考虑这些“不耐光”残留物的光解如何影响酶活性，将闪光光解数据与失活联系起来。这一分析表明，母鸡溶菌酶和木瓜蛋白酶被灭活的一个重要的色氨酸残基的光解，牛胰蛋白酶被灭活的色氨酸残基附近的关键催化丝氨酸和其他途径的激发酪氨酸和半胱氨酸的激发，有效的光电离酪氨酸和核糖核酸酶A是不是一个重要的灭活反应，并在subtilisn嘉士伯的芳香族残基是光敏的。
The photoionization of aromatic residues constitutes a major initial photochemical reaction in the flash photolysis of proteins at gamma greater than 250 nm. The ejected electrons have been observed as eaq- and the disulphide bridge electron adduct, and also must be trapped at unidentified sites. The number of tryptophyl (or tyrosyl) residues photo-ionized at 5 musec delay is approximately equal to the number of exposed residues. The flash photolysis data have been related to inactivation by considering how photolysis of these "photolabile" residues can affect enzymic activity, based on the microstructure and available information about permanent alterations and residue specificities. This analysis indicates that hen lysozyme and papain are inactivated by photolysis of an essential Trp residue, that bovine trypsin is inactivated by photolysis of a Trp residue adjacent to the key catalytic Ser and other pathways initiated by excitation of Tyr and Cys, that the efficient photoionization of Tyr and RNase A is not an important inactivating reaction, and that aromatic residues in subtilisn Carlsberg are photosensitive.