Spin Relaxation Methods for Characterizing Picosecond-Nanosecond and Microsecond-Millisecond Motions in Proteins
Spin Relaxation Methods for Characterizing Picosecond-Nanosecond and Microsecond-Millisecond Motions in Proteins
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用于表征蛋白质中皮秒-纳秒和微秒-毫秒运动的自旋弛豫方法
DOI：
--
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
C. Bracken
中科院分区：
文献类型：
--
作者：
A. Palmer;C. Bracken
蛋白质和其他大分子的时间依赖性构象波动通过统计力学原理与多种生物物理现象相关，包括热力学稳定性、折叠、分子识别和催化。异核（2H、13C 和 15N）NMR 自旋弛豫光谱是一种强大的实验方法，可用于全局表征溶液中大分子的构象动力学，从而探测生物功能。皮秒-纳秒时间尺度上的分子动力学可以使用实验室框架自旋-晶格弛豫率常数、自旋-自旋弛豫率常数和异核欧沃豪瑟增强来表征。无模型形式主义根据分子的整体旋转扩散张量以及每个核自旋的广义序参数和有效内相关时间来参数化弛豫数据。序参数和相关时间表征了负责核自旋弛豫的偶极、化学位移各向异性和四极相互作用的主轴重新定向运动的幅度和时间尺度。描述了使用广义序参数来研究牛钙结合蛋白 D9k、大肠杆菌核糖核酸酶 H 和人纤连蛋白 III 型结构域中肽主链运动的配体结合和能量景观的熵贡献。生物大分子中微秒-毫秒时间尺度上发生的构象交换过程可以通过 Carr-Purcell-Meiboom-Gill 和 R1 实验进行研究。使用这些实验测量汇率受到前一个实验中可行的自旋回波延迟范围有限和后者中可获得的射频场强度范围有限的阻碍。尽管如此，由 Carr-Purcell-Meiboom-Gill 技术确定的横向弛豫速率常数的温度依赖性可用于定义交换过程的激活势垒，而无需精确了解交换速率常数。非共振 R1ρ 实验在旋转框架中提供了比所施加的射频场强大得多的有效场，可用于测量短至 10 μs 的交换时间常数。该方法适用于大肠杆菌核糖核酸酶 H 和来自人腱蛋白的第三个纤连蛋白 III 型结构域。
Time-dependent conformational fluctuations of proteins and other macromolecules are related by statistical mechanical principles to diverse biophysical phenomena, including thermodynamic stability, folding, molecular recognition, and catalysis. Heteronuclear (2H, 13C, and 15N) NMR spin relaxation spectroscopy constitutes a powerful experimental approach for globally characterizing conformational dynamics of macromolecules in solution, and consequently for probing biological function. Molecular dynamics on picosecond-nanosecond time scales can be characterized using the laboratory frame spin-lattice relaxation rate constant, the spin-spin relaxation rate constant and heteronuclear Overhauser enhancement. The model-free formalism parameterizes the relaxation data in terms of an overall rotational diffusion tensor for the molecule and a generalized order parameter and effective internal correlation time for each nuclear spin. The order parameter and correlation time characterize the amplitude and time scale for reorientational motions of the principal axes of the dipolar, chemical shift anisotropy and quad-rupolar interactions responsible for relaxation of the nuclear spin. The use of the generalized order parameter to investigate entropic contributions to ligand binding and energy landscapes for peptide backbone motions in bovine calbindin D9k, Escherichia coli ribonuclease H, and human fibronectin type III domains are described. Conformational exchange processes occurring on microsecond-millisecond time scales in biological macromolecules can be studied by Carr-Purcell-Meiboom-Gill and R1 experiments. The measurement of exchange rates using these experiments is hindered by the limited range of spin-echo delays that are feasible in the former experiment and the limited range of radiofrequency field strengths accessible in the latter. Nonetheless, the temperature dependence of the transverse relaxation rate constant determined by the Carr-Purcell-Meiboom-Gill technique can be used to define the activation barrier for the exchange process without precise knowledge of the exchange rate constant. Off-resonance R1ρ experiments provide effective fields in the rotating frame that are much larger than the applied radiofrequency field strengt and can be used to measure exchange time constants as short as 10 μs. The methods are applied to Escherichia coli ribonuclease H and the third fibronectin type III domain from human tenascin.
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影响因子：
2.9
作者：
Lefevre, JF;Dayie, KT;Wagner, G
通讯作者：
Wagner, G
无模型公式的检验。
DOI：
10.1006/jmrb.1994.1127
发表时间：
1994
期刊：
Journal of magnetic resonance. Series B
影响因子：
--
作者：
Schurr,JM;Babcock,HP;Fujimoto,BS
通讯作者：
Fujimoto,BS
影响因子：
5.6
作者：
DICKINSON, CD;VEERAPANDIAN, B;ELY, KR
通讯作者：
ELY, KR
通过二维质子检测 15N NMR 光谱研究负载钙的钙结合蛋白 D9k 的主链动力学。
影响因子：
2.9
作者：
Kördel,J;Skelton,NJ;Akke,M;Palmer3rd,AG;Chazin,WJ
通讯作者：
Chazin,WJ
影响因子：
5.7
作者：
Carr, PA;Erickson, HP;Palmer, AG
通讯作者：
Palmer, AG