【摘要】 花粉管的细胞质粗提液在钙离子的调节下,类似其它非肌细胞,表现出凝胶化和收缩运动两相过程。在低钙浓度条件下,细胞质形成凝胶,随着钙离子浓度的提高,细胞质表现出依赖于ATP的收缩运动。收缩的原生质团内含有许多丝状结构,SDS聚丙烯酰胺凝胶电泳分析结果表明,丝状结构主要由肌动蛋白,肌球蛋白和105kD、67kD、48kD、38kD、34kD和28kD,8种蛋白质组成。该结果表明,在钙离子调节下,肌动蛋白可由单体或寡聚体的形式转变为纤维状结构,并与其它蛋白质相互作用联结成更高级的结构形式,从而使细胞质形成凝胶,通过肌动蛋白与肌球蛋白的相互作用,将ATP的化学能转变为机械功,产生收缩运动。更多还原

【Abstract】 The crude extracts of pollen tubes,like other nonmuscle cells,showed gelation at low Ca²⁺ concentrations and ATP-dependent contraction at higher Ca²⁺ concentrations.The contracted cytoplasmic clots contained a lot of filaments which were mainly composed of actin, myosin,105 kD,67 kD,48 kD,38 kD.34 kD and 28 kD proteins.It is likely that Ca²⁺ are able to mediate tranformation of actin from a less ordered state to a more oriented filaments,which interact with actin-binding proteins to form the filamentous network,thus to induce the gel formation of cytoplasm,to regulate the interaction of actin and myosin which transform the chemical energy of ATP into mechanical work of contractile movement of cytoplasm,更多还原