Beall P T, Hazlewood C F, Rao P N
Science. 1976 May 28;192(4242):904-7. doi: 10.1126/science.1273575.
Nuclear magnetic resonance relaxation time (T1) of the intracellular water protons and water content were measured in synchronized HeLa cells. The T1 was maximum (1020 milliseconds) in mitotic and minimum (534 milliseconds) in S phase cells. The cyclic pattern of T1 values correlated well with the chromosome condensation cycle. By treating cells with spermine, it was possible to alter T1 without a significant change in the water content. The results of this study suggest that an additional variable, namely, the conformational state of macromolecules, should be incluced in any expression explaining the shortened relaxation times of water protons in biological systems.
在同步化的HeLa细胞中测量了细胞内水质子的核磁共振弛豫时间（T1）和含水量。T1在有丝分裂期细胞中最大（1020毫秒），在S期细胞中最小（534毫秒）。T1值的周期性模式与染色体浓缩周期密切相关。通过用精胺处理细胞，可以改变T1而含水量无显著变化。本研究结果表明，在任何解释生物系统中水质子弛豫时间缩短的表达式中，都应纳入另一个变量，即大分子的构象状态。
