用马来酰亚胺自旋标记研究库存血红细胞膜蛋白质构象

用两种马来酰亚胺自旋标记物—马来酰亚胺Ⅰ和马来酰亚胺Ⅴ研究了红细胞膜蛋白质构象及巯基结合位点性质在ACD-B方库存血保存期间的动态变化。结果发现,在35天的血液保存期间,马来酰亚胺Ⅰ所标记红细胞膜的S/w值很快下降到一低水平,而马来酰亚胺Ⅴ所标记红细胞膜的旋转相关时间则呈现迅速下降后缓慢升高的双相性变化。作者结合膜蛋白构象及其周围微观环境进行了讨论。

AN INVESTIGATION OF CONFIGURATION OF ERYTHROCYTE MEMBRANE PROTEINS WITH MALEIMIDE SPIN LABELS DURING BLOOD PRESERVATION

Two maleimide spin labels, malcimide I and maleimide V, were used to investigate the dynamic changes of the conf ipura t ion and sulfhydryl binding sites of erythrocyte membranc protein- within a 35-day period of ACD-B blood preserved. The results showed: during the preservation period, the S/W ratio ealculated from ESR spectra of maleimide I-labelled erythrocytes decreased rapidly to a lower level; the rotational eorrtlation time (t,.) inferred from ESR spectra of maleimide V-lahelled erythrocytes decreased rapidly in the first week but increased slowly to the initial level in the later stage. The decrease of S /W ratio demonstrated configuration changes of erythrocyte membrane proteins. The changes of rotational correlation time might reflect that the micro-viscosity in the superficial aqueous portion around the membrane proteins,perhaps including the adjacent superficial lipid environment ,undcrwent a bipha-sic change, i.e, decreased rapidly then increased slowly during preservation.