Aliphatic groups of sperm whale myoglobin: 13C NMR study.
Aliphatic groups of sperm whale myoglobin: 13C NMR study.
复制标题
抹香鲸肌红蛋白的脂肪族基团：13C NMR 研究。
DOI：
10.1073/pnas.76.3.1059
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发表时间：
1979
影响因子：
11.1
通讯作者：
F. Gurd
中科院分区：
文献类型：
--
作者：
R. Wittebort;T. Rothgeb;A. Szabó;F. Gurd
在67.9兆赫下对抹香鲸蓝铁肌红蛋白的13C核磁共振光谱的脂肪族区域进行了研究。在四甲基硅烷下场9 ~ 29 ppm的光谱范围内，观察到50个部分分解或完全分解的共振，代表了分子中至少一半的脂肪族碳。对这些共振的自旋晶格弛豫时间（T1）和核Overhauser增强的分析表明，脂肪族侧链具有相当大的运动自由度。在9 ~ 15ppm的光谱范围内，观察到8个单碳共振，并暂定为9个异亮氨酸残基中的8个的Cdelta 1。在至少五种情况下，异亮氨酸侧链的重定向运动不能仅仅通过cδ 1甲基的旋转来表征。与数据相符的最简单模型是具有2度内旋的受限扩散模型[Wittenbort， R. J. & Szabo, a .(1978)]。[物理学报，1722—1736]。根据肌红蛋白分子内的堆积密度，这些结果被认为意味着埋藏的脂肪残基的协调运动。
The aliphatic region of the 13C NMR spectrum of sperm whale cyanoferrimyoglobin has been examined at 67.9 MHz. Fifty partially resolved or well-resolved resonances, representing at least half of the aliphatic carbons in the molecule, are observed in the spectral region from 9 to 29 ppm downfield of tetramethylsilane. Analyses of the spin lattice relaxation times (T1) and nuclear Overhauser enhancements for these resonances reveal considerable motion freedom of the aliphatic side chains. In the spectral region from 9 to 15 ppm, eight single carbon resonances are observed and tentatively assigned to Cdelta 1 of eight of the nine isoleucine residues. In at least five cases the reorientational motion of the isoleucine side chains could not be characterized solely by rotation of the Cdelta 1 methyl groups. The simplest model consistent with the data is a restricted diffusion model with two degrees of internal rotation [Wittenbort, R. J. & Szabo, A. (1978) J. Chem. Phys. 69, 1722--1736]. In light of the packing densities within the myoglobin molecule these results are taken to imply concerted motions of the buried aliphatic residues.