Fung L W, Lu H Z, Hjelm R P, Johnson M E
Department of Chemistry, Loyola University of Chicago, IL 60626.
Life Sci. 1989;44(11):735-40. doi: 10.1016/0024-3205(89)90385-8.
Previous high resolution proton NMR data on human erythrocyte spectrin molecules has indicated the existence of regions exhibiting rapid internal motions within the intact molecules [L. W.-M. Fung, H.-Z. Lu, R. P. Hjelm, jr, M. E. Johnson, FEBS Lett., 197, 234 (1986)]. We have extended the studies by developing quantitative NMR methods to determine the fraction of spectrin protons exhibiting rapid internal motions, in both the isolated molecule and within the spectrin-actin network. Using both one-pulse and spin echo pulse sequences, we find that the fraction of the protons in rapid motion is about 15% of the total protons in the spectrin molecule at 37 degrees C in phosphate buffer with 150 mM NaCl at pH 7.4. Quantitative information on these rapid motions will be important in understanding the structural, mechanical and functional properties of spectrin molecules, as well as in understanding filamentous protein structures in general.
先前有关人类红细胞血影蛋白分子的高分辨率质子核磁共振数据表明，完整分子内存在表现出快速内部运动的区域[L. W.-M. 冯、H.-Z. 卢、R. P. 赫尔姆、小M. E. 约翰逊，《欧洲生物化学会联合会快报》，197, 234 (1986)]。我们通过开发定量核磁共振方法来扩展研究，以确定在分离分子和血影蛋白 - 肌动蛋白网络中表现出快速内部运动的血影蛋白质子的比例。使用单脉冲和自旋回波脉冲序列，我们发现在37摄氏度、pH 7.4、含有150 mM NaCl的磷酸盐缓冲液中，处于快速运动状态的质子比例约为血影蛋白分子中总质子数的15%。关于这些快速运动的定量信息对于理解血影蛋白分子的结构、力学和功能特性，以及一般情况下理解丝状蛋白质结构都将非常重要。
