文章基本信息

标题：Photodestruction of acetylcholinesterase
本地全文：下载
作者：W H Bishop ; L Henke ; J P Christopher 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：4
页码：1980-1982
DOI：10.1073/pnas.77.4.1980
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Ultraviolet irradiation of 11S acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7 ) produces a loss of tryptophan fluorescence which is best described as the sum of two separable first-order processes, one much more rapid than the other. In addition, the enzyme undergoes an all-or-none inactivation that is monotonically first order. Simultaneous with activity loss, photoscission takes place and results in a molecular weight drop of 1 x 10(5); this decrease is first order with a rate constant identical to that for enzymatic inactivation. These processes are accompanied by apparent conformational changes, as shown by circular dichroic and difference absorption spectra. The relative photochemical inactivation efficiency of incident light is unity when corrected for the wavelength dependence of fluorescence excitation, which is consistent with an efficient Forster resonance transfer of energy among the aromatic chromophores. The extreme sensitivity of acetylcholinesterase to photodestruction upon photon absorption and the several events that follow it not only suggest that these findings might be a basis for a useful molecular probe of the structure of this enzyme, but also indicate that additional care should be taken when conducting spectroscopic studies in the UV region.