Comparison of (13)C(alpha)H and (15)NH backbone dynamics in protein GB1.
Comparison of (13)C(alpha)H and (15)NH backbone dynamics in protein GB1.
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蛋白质 GB1 中 (13)C(α)H 和 (15)NH 主链动力学的比较。
DOI：
10.1110/ps.0228703
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Mayo,KevinH
中科院分区：
文献类型：
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作者：
Idiyatullin,Djaudat;Nesmelova,Irina;Daragan,VladimirA;Mayo,KevinH
本研究提供了链球菌蛋白G，GB 1的56个残基免疫球蛋白结合结构域中骨架CαH和NH内部运动的位点分辨实验视图。使用在三个共振频率（1H频率为500、600和800 MHz）下获得的13 C αH和15 NH NMR弛豫数据[T1、T2和NOE]，计算谱密度函数为F（ω）= 2ωJ（ω），以提供一种模型无关的方法来可视化和分析GB 1中主链基团的内部运动相关时间分布。F（ω）曲线的线增宽表明所有CαH和NH基团都存在纳秒时间尺度的内部运动（0.8 ~ 5 nsec）。F（ω）曲线的反卷积有效地分离了整体翻滚和内部运动相关时间分布，从而产生比使用标准无模型方法确定的更精确的序参数。与NH基团相比，CαH的内部运动在纳秒时间尺度上分布更广，CαH的有序参数更大，这与CαH涨落的相关键旋转有关. NH基团的运动参数在结构上更相关，例如，NH顺序参数对于β-折叠和螺旋的更结构化区域中的残基较大，而对于环和转角中的残基通常较小。这很可能与观察到NH序参数与氢键相关有关。这项研究有助于对蛋白质动力学的一般理解，并证实了一种替代和更容易的方法来分析NMR弛豫数据。
This study presents a site‐resolved experimental view of backbone CαH and NH internal motions in the 56‐residue immunoglobulin‐binding domain of streptococcal protein G, GB1. Using13CαH and15NH NMR relaxation data [T1,T2, and NOE] acquired at three resonance frequencies (1H frequencies of 500, 600, and 800 MHz), spectral density functions were calculated asF(ω) = 2ωJ(ω) to provide a model‐independent way to visualize and analyze internal motional correlation time distributions for backbone groups in GB1. Line broadening inF(ω) curves indicates the presence of nanosecond time scale internal motions (0.8 to 5 nsec) for all CαH and NH groups. Deconvolution ofF(ω) curves effectively separates overall tumbling and internal motional correlation time distributions to yield more accurate order parameters than determined by using standard model free approaches. Compared to NH groups, CαH internal motions are more broadly distributed on the nanosecond time scale, and larger CαH order parameters are related to correlated bond rotations for CαH fluctuations. Motional parameters for NH groups are more structurally correlated, with NH order parameters, for example, being larger for residues in more structured regions of β‐sheet and helix and generally smaller for residues in the loop and turns. This is most likely related to the observation that NH order parameters are correlated to hydrogen bonding. This study contributes to the general understanding of protein dynamics and exemplifies an alternative and easier way to analyze NMR relaxation data.