硒与红细胞血影收缩蛋白(Spectrin)作用导致构象变化

从人红细胞膜提取血影收缩蛋白(Spectrin),研究不同浓度Na_2SeO_3与其作用后的构象变化.用N—3—芘]—马来酰胺(N-3-P]M)作荧光探针标记Spectrin,经SDS处理后,其荧光强度随硒的浓度增加而逐步降低.但未经SDS处理的样品,加入0.2—1.0ppm的Na_2SeO_3后反而使荧光强度有所增加.Spectrin经硒作用与未经作用相比较在色氨酸内源荧光、丹磺酰氯(DNS-Cl)标记后(DNS-Spectrin)的荧光光谱以及色氨酸残基与DNS基团间的能量转移实验结果均有明显的差别.这反映Spectrin的巯基经与硒作用后会导致构象的变化.

Se INDUCES CONFORMATION CHANGE OF SPECTRIN FROM HUMAN ERYTHROCYTE MEMBRANE

The conformation change of spectrin extracted from human ery-throcyte membrane after treatment with various concentrations of Na2SeO3 has been studied. The fluorescence intensity for the N-(3-pyrenyl)-maleimide--lab-elled spectrin in the presence of SDS was decreasing with increasing of Na2SeO3 concentration. However, the fluorescence intensity for the labelled spectrin pretreated with 0.2-1.0 ppm Na2SeO3 was even increasing in the absence of SDS. Conformation change of spectrin after treatment with Na2SeO3 was further detected by measuring tryptophan intrinsic fluorescence, fluorescence spectra of Dansyl-Cl-conjugated spectrin and energy transfer efficiency from tryptophane residue to the DNS group of DNS-conjugated spectrin, Obtained results may indicate that Na2SaO3 can induces conformation change of human erythrocyte membrane spectrin by reacting with its SH group.