CROSS RELAXATION AND SPIN DIFFUSION IN PROTON NMR OF HYDRATED COLLAGEN
CROSS RELAXATION AND SPIN DIFFUSION IN PROTON NMR OF HYDRATED COLLAGEN
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DOI：
10.1038/265521a0
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发表时间：
1977-01-01
期刊：
影响因子：
64.8
通讯作者：
SAMULSKI, ET
中科院分区：
文献类型：
--
作者：
EDZES, HT;SAMULSKI, ET
水的质子核磁共振被广泛用于探测生物系统中水分子的分子动力学，如蛋白质溶液、水合大分子、细胞和组织。核磁弛豫率r1（自旋-晶格）和r2（自旋-自旋）可以根据水分子的旋转运动来分析1 - 3。这个分析中的一个关键假设是水的质子弛豫独立于大分子的质子弛豫。Kimmich和noack4 - 6声称，由于自旋扩散，质子自旋-晶格弛豫的假设可能是不正确的，但自旋扩散在水合生物样品中的明确证据尚未报道。我们发现水合胶原中的质子自旋-晶格弛豫行为主要是由自旋扩散导致的水质子和大分子质子之间的交叉弛豫所控制的；大分子自旋-晶格弛豫对水质子r1有显著贡献。
PROTON NMR of water is being used extensively to probe the molecular dynamics of water molecules in biological systems such as protein solutions, hydrated macromolecules, cells and tissue. The nuclear magnetic relaxation ratesR1(spin–lattice) andR2(spin–spin) can be analysed in terms of the rotational motions of the water molecules1–3. A crucial assumption in this analysis is that the proton relaxation of the water proceeds independently of that of the macromolecules. Kimmich and Noack4–6claim that this assumption may be incorrect for proton spin–lattice relaxation because of spin diffusion, but clear evidence of spin diffusion in hydrated biological samples has not been reported. We show here that the proton spin–lattice relaxation behaviour in hydrated collagen is dominated by cross relaxation between the water protons and the macromolecular protons as a result of spin diffusion; the macromolecular spin–lattice relaxation contributes significantly to the water protonR1.