Light- and dark-adapted bacteriorhodopsin, a time-resolved neutron diffraction study.
Light- and dark-adapted bacteriorhodopsin, a time-resolved neutron diffraction study.
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光适应和暗适应的细菌视紫红质，一种时间分辨中子衍射研究。
DOI：
10.1016/0005-2736(90)90331-h
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
G. Büldt
中科院分区：
文献类型：
--
作者：
N. Dencher;G. Papadopoulos;D. Dresselhaus;G. Büldt
最近，中子衍射实验揭示了细菌视紫红质 (BR) 的蛋白质构象在光适应基态和质子泵浦光循环的 M 中间体之间的良好解析和可逆变化（Dencher, Dresselhaus, Zaccai 和 Büldt (1989) Proc. Natl. Acad. Sci. USA 86, 7876–7879）。这些变化是由光诱导的生色团视网膜从全反式异构化为 13-顺式构型引发的。暗适应紫色膜含有两种色素的混合物，以全反式或 13-顺式视黄醛异构体作为发色团。采用时间分辨中子衍射技术，在两种基态物质 13-cis-BR 和全反式-BR 之间的转变过程中，在高达 7 Å 的分辨率范围内，没有观察到蛋白质构象的变化。这与全反式 BR 向 13-顺式 BR 的转化涉及 C15 N 希夫碱基键的额外异构化这一事实相符，这与 M 形成相反，最大限度地减少了视网膜位移并将希夫碱保留在原始蛋白质环境中。此外，没有迹象表明在明暗适应过程中紫色膜中的水分子会大规模重新分布。
Recently, neutron diffraction experiments have revealed well-resolved and reversible changes in the protein conformation of bacteriorhodopsin (BR) between the light-adapted ground state and the M-intermediate of the proton pumping photocycle (Dencher, Dresselhaus, Zaccai and Büldt (1989) Proc. Natl. Acad. Sci. USA 86, 7876–7879). These changes are triggered by the light-induced isomerization of the chromophore retinal from the all-trans to the 13-cis configuration. Dark-adapted purple membranes contain a mixture of two pigment species with either the all-trans- or 13-cis-retinal isomer as chromophore. Employing a time-resolved neutron diffraction technique, no changes in protein conformation in the resolution regime of up to 7 Å are observed during the transition between the two ground-state species 13-cis-BR and all-trans-BR. This is in line with the fact that the conversion of all-trans BR to 13-cis-BR involves an additional isomerization about the C15 N Schiff's base bond, which in contrast to M formation minimizes retinal displacement and keeps the Schiff's base in the original protein environment. Furthermore, there is no indication for large-scale redistribution of water molecules in the purple membrane during light-dark adaptation.
影响因子：
2.9
作者：
P. Scherrer;M. Mathew;W. Sperling;W. Stoeckenius
通讯作者：
P. Scherrer;M. Mathew;W. Sperling;W. Stoeckenius
影响因子：
3.4
作者：
M. Tsuda;T. Ebrey
通讯作者：
M. Tsuda;T. Ebrey