Nuclear magnetic resonance determination of ligand-induced conformational changes in myoglobin.
Nuclear magnetic resonance determination of ligand-induced conformational changes in myoglobin.
复制标题
核磁共振测定配体诱导的肌红蛋白构象变化。
DOI：
10.1016/0022-2836(70)90050-1
复制
发表时间：
1970
影响因子：
5.6
通讯作者：
W. Blumberg
中科院分区：
文献类型：
--
作者：
R. Shulman;K. Wüthrich;T. Yamane;D. Patel;W. Blumberg
我们报道了220 MHz的脱氧肌红蛋白和肌红蛋白与氧、一氧化碳和乙基异氰化物的三种抗磁性络合物的高分辨率质子核磁共振的结果。我们强调的是芳环，特别是卟啉环的环电流使其偏离正常位置的共振，因为这些环电流的移动对观察到的质子和环的相对坐标的变化非常敏感。在−6.1p.m的一次特殊共振，强度约为3个质子，被归因于一个芳香残基的质子，该残基被血红素基团的环流前移。这种共振的一个可能来源是Phe CD1。观测到的下午0.2点这种共振的变化。氧合作用相当于一个埃单位的十分之几的运动。对Mb‡和MbO2的完整光谱的比较表明，由于脂肪族残基的甲基引起的共振峰的氧合作用略有较大的位移，运动约为0.5A，两者之间有许多微小的差异，从0.1p.pm到0.2p.pm。这表明了氧气作用下广泛存在的微小结构变化。不同连接形式之间的环电流移位共振的差异，包括氰基铁肌红蛋白，表明当配体改变时，蛋白质中存在结构差异。
We report the results of a high-resolution proton nuclear magnetic resonance at 220 MHz of deoxymyoglobin and three diamagnetic complexes of myoglobin with oxygen, carbon monoxide and ethylisocyanide. We emphasize the resonances which are shifted from their normal positions by ring currents from aromatic rings, particularly the porphyrin ring, because these ring current shifts are very sensitive to changes of the relative co-ordinates of the observed protons and the ring. A specific resonance at −6.1 p.p.m., with intensity of about three protons, has been attributed to the protons of an aromatic residue, shifted upfield by the ring currents of the heme group. A possible origin of this resonance is Phe CD1. The observed change of this resonance of 0.2 p.p.m. upon oxygenation corresponds to a movement of a few tenths of an angstrom unit. Slightly larger shifts upon oxygenation of resonances attributed to methyl groups of aliphatic residues are interpreted in terms of movements of about 0.5 Å.A comparison of the complete spectra of Mb‡and MbO2shows that there are many small differences of 0.1 to 0.2 p.p.m. which indicate widespread small structural changes upon oxygenation. Differences in the ring-current-shifted resonances amongst various ligated forms including cyanoferrimyoglobin, indicate the existence of structural differences in the protein when the ligand is changed.