Conformation and dynamics of [3-13C]Ala- labeled bacteriorhodopsin and bacterioopsin, induced by interaction with retinal and its analogs, as studied by 13C nuclear magnetic resonance.
Conformation and dynamics of [3-13C]Ala- labeled bacteriorhodopsin and bacterioopsin, induced by interaction with retinal and its analogs, as studied by 13C nuclear magnetic resonance.
复制标题
通过 13C 核磁共振研究，通过与视网膜及其类似物相互作用诱导[3-13C]Ala 标记的细菌视紫红质和细菌视紫红质的构象和动力学。
DOI：
10.1021/bi960274s
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发表时间：
1996
期刊：
影响因子：
2.9
通讯作者：
H. Saitô
中科院分区：
文献类型：
--
作者：
S. Tuzi;S. Yamaguchi;A. Naito;R. Needleman;J. Lanyi;H. Saitô
记录了[3-13C] ala标记的细菌视紫红质（bR）、细菌视紫红质（bO）和再生bR与视网膜或bO复合物与视网膜类似物的13C核磁共振（NMR）波谱，以了解载脂蛋白（bO）在有或没有视网膜或其类似物的情况下的构象和动力学变化。首先，我们利用A53V和A53G蛋白的13C核磁共振峰与野生型bR和bO的13C核磁共振峰进行比较，将在16.3 ppm共振的13C核磁共振峰分配给bR和bO的Ala 53，它似乎与前者的Schiff碱基位置的Lys 216侧链接触。在去除视网膜后观察到载脂蛋白和bR之间的特征光谱差异：在16.4、15.9和16.9 ppm时峰强度的变化是显著的。我们发现环（17.4 ppm）和跨膜α II螺旋区（15.9 ppm）在视网膜被移除时获得了运动自由，相关时间为10(-5)s，通过旋转框架中的质子自旋晶格弛豫时间检测。在bO中加入视网膜再生bR时，记录到与天然bR非常相似的13C核磁共振谱。另一方面，加入视网膜类似物视黄醇或β -离子酮，它们结合在视网膜结合位点，但不能与载脂蛋白形成希夫碱，引起与bR不同的明显光谱变化，这表现在13C化学位移的位移上。这些光谱变化必须归因于载脂蛋白在蛋白质中不同位置的显着构象变化，包括由载脂蛋白与发色团之间的修饰相互作用诱导的Ala 53位点。
13C nuclear magnetic resonance (NMR) spectra of [3-13C]Ala-labeled bacteriorhodopsin (bR), bacterioopsin (bO), and regenerated bR with retinal or bO complex with retinal analogs were recorded in order to gain insights into how the conformation and dynamics of apoprotein (bO) vary with or without retinal or its analogs. First, we assigned the 13C NMR peak resonating at 16.3 ppm to Ala 53 of both bR and bO, which appears to contact the side chain of Lys 216 at the site of the Schiff base in the former, utilizing the 13C NMR peaks of A53V and A53G proteins in comparison with those of wild-type bR and bO. Characteristic spectral differences between the apoprotein and bR were observed upon removal of the retinal: the changes of the peak intensities at 16.4, 15.9, and 16.9 ppm are notable. We found that the loops (17.4 ppm) and transmembrane alpha II helical region (15.9 ppm) acquired motional freedom with a correlation time of 10(-5)s when the retinal was removed, as detected by proton spin-lattice relaxation times in the rotating frame. A 13C NMR spectrum very similar to that of native bR was recorded when bR was regenerated by addition of retinal to bO. On the other hand, the addition of the retinal analogs retinol or beta-ionone, which are bound in the retinal binding site but are incapable of forming a Schiff base to the apoprotein, caused distinct spectral changes different from those of bR, as manifested from the displacements of 13C chemical shifts. These spectral changes must be ascribed to significant conformational changes of apoprotein at various locations in the protein, including the site of Ala 53 induced by modified interaction between the apoprotein and chromophore.