Backbone dynamics of (1–71)- and (1–36)bacterioopsin studied by two-dimensional 1H-15N NMR spectroscopy
Backbone dynamics of (1–71)- and (1–36)bacterioopsin studied by two-dimensional 1H-15N NMR spectroscopy
复制标题
通过二维 1H-15N NMR 光谱研究 (1–71)- 和 (1–36) 细菌红蛋白的骨架动力学
DOI：
10.1007/bf00211774
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发表时间：
1995
影响因子：
2.7
通讯作者：
A. Arseniev
中科院分区：
文献类型：
--
作者：
V. Orekhov;K. Pervushin;D. Korzhnev;A. Arseniev
摘要采用二维质子检测的h - 15n核磁共振波谱技术，在600和400 MHz两种频率下，研究了溶解于两种介质（甲醇-氯仿（1:1）、0.1 M 2HCO2NH4或SDS胶束）中的均匀15n标记菌素片段（残基1-71和1-36）的主链动力学。利用一组不同速率的CPMG自旋锁脉冲序列阐明了构象交换对单个氮的横向弛豫速率的贡献，并且基本上被高频CPMG自旋锁抑制。我们发现SDS胶束中（1-71）细菌蛋白酶的大部分主干酰胺基团参与了103 ~ 104 s-1的构象交换过程。这种构象交换被认为是由于（1-71）细菌视素的两个α-螺旋之间的相互作用，因为环区肽键的水解导致交换线展宽消失。采用Lipari和Szabo的无模型方法解释了15N松弛率和1H-15N NOE值[Lipari， G. and Szabo， A. (1982) J. Am]。化学。Soc。[j].环境科学与技术，2016,33(4):446 - 459。除了分子的整体旋转外，多肽的主干N-H载体还参与两种类型的内部运动：快速运动，在<20秒的时间尺度上，和中间运动，在接近1秒的时间尺度上。α-螺旋拉伸中的中间动力学主要归因于弯曲运动。在Pro50附近的残基中，中间运动的序参量也有所下降，这表明分子的整体旋转扩散具有各向异性。通过中间运动序参量的大幅下降，可以识别出明显的移动区域，这些区域对应于N端和c端，以及连接（1-71）细菌视素α-螺旋的环。α-螺旋在毫秒和纳秒时间尺度上的内部动力学应该考虑到细菌视紫红质功能模型的发展。
SummaryThe backbone dynamics of uniformly 15N-labelled fragments (residues 1–71 and 1–36) of bacterioopsin, solubilized in two media (methanol-chloroform (1:1), 0.1 M 2HCO2NH4, or SDS micelles) have been investigated using 2D proton-detected heteronuclear 1H-15N NMR spectroscopy at two spectrometer frequencies, 600 and 400 MHz. Contributions of the conformational exchange to the transverse relaxation rates of individual nitrogens were elucidated using a set of different rates of the CPMG spin-lock pulse train and were essentially suppressed by the high-frequency CPMG spin-lock. We found that most of the backbone amide groups of (1–71)bacterioopsin in SDS micelles are involved in the conformational exchange process over a rate range of 103 to 104 s-1. This conformational exchange is supposed to be due to an interaction between two α-helixes of (1–71)bacterioopsin, since the hydrolysis of the peptide bond in the loop region results in the disappearance of exchange line broadening. 15N relaxation rates and 1H-15N NOE values were interpreted using the model-free approach of Lipari and Szabo [Lipari, G. and Szabo, A. (1982) J. Am. Chem. Soc., 104, 4546–4559]. In addition to overall rotation of the molecule, the backbone N-H vectors of the peptides are involved in two types of internal motions: fast, on a time scale <20 ps, and intermediate, on a time scale close to 1 ns. The intermediate dynamics in the α-helical stretches was mostly attributed to bending motions. A decrease in the order parameter of intermediate motions was also observed for residues next to Pro50, indicating an anisotropy of the overall rotational diffusion of the molecule. Distinctly mobile regions are identified by a large decrease in the order parameter of intermediate motions and correspond to the N- and C-termini, and to a loop connecting the α-helixes of (1–71)bacterioopsin. The internal dynamics of the α-helixes on the millisecond and nanosecond time scales should be taken into account in the development of a model of the functioning bacteriorhodopsin.
影响因子：
5.6
作者：
HENDERSON, R;BALDWIN, JM;DOWNING, KH
通讯作者：
DOWNING, KH