【摘要】 芹菜韧皮部初步纯化的肌动蛋白,用SDS聚丙烯酸胺凝胶电泳进行分离,得到与兔骨胳肌的肌动蛋白相似的迁移率,其分子量为43 000道尔顿,与免肌肌动蛋白的分子量相一致。韧皮部的G-肌动蛋白聚合成F-肌动蛋白,在电子显微镜下观察到直径5～7nm肌动蛋白的微丝。用兔肌的重酶解肌球蛋白处理并负染后,在电镜下观察到箭头状装饰。韧皮部的F-肌动蛋白能激活兔肌重酶解肌球蛋白ATP酶的活性,酶活性可被激活8倍以上。证明芹菜韧皮部中确实存在肌动蛋白。更多还原

【Abstract】 Actin is present in the isolated phloem of celery (Apium graveolens L. var.dulce D. C.). The phloem is isolated from the petioles of celery and its contentsare extracted with a Tris-HCl buffer. Na dodecyl sulfate polyacrylamide gelelectrophoresis of the phloem extract demonstrates that its electrophoretic mobilityis the same with that of rabbit actin. The molecular weight of celery actin is43000 daltons which is identical with that of rabbit actin. In the phloem tissue actinis in the form of microfilaments 5～7 nm in diameters which are visible under elec-tron microscope. When the microfilaments are treated with heavy meromyosinof rabbit muscle and negatively stained, arrowhead decoration is observed. F-actin of phloem tissue is able to activate the heavy meromyosin ATPase, its activityis 8 fold higher than the control. It is suggested that the phloem actin may beresponsible for all the mobility in plants.更多还原