EFFECT OF Na_2SeO_3 ON THE INTERATION OF SPECTRIN WITH ACTIN
Na_2SeO_3对血影收缩蛋白(spectrin)与肌动蛋白(actin)相互作用的影响

No obvious effect was observed on the polymerization of actin by Na2SeO3. However, in the presence of human erythrocyte spectrin, Na2SeO3 could markedly enhance the polymerization rate of actin.Such Se effect was concentration -dependent. In the presence of trace amount of Na2SeO3 (0.1-10.0 ppm) both nucleation and elongation rates of actin polymerization were detected, but an increase result appeared only with a Na2SeO3 concentration of 0.5-5.0 ppm. An opposite effect of Na2SeO3 was observed at a higher concentration. We also found that sulfhydryl reagen NEM could eliminate the Se effect. It may deduced that in the presence of an appropriate amount of Na2SeO3 the association of spectrin with actin oligomers, and hence the stabilization of erythrocyte membrane skeleton might be strengthened in consequence of the confor-mational changes of spectrins induced by the interaction of their SH groups with Na2SeO3.