摘要
用水溶性多聚物 ( dextran T5 0 0 PEG 335 0 )两相法制备盐生杜氏藻细胞质膜 ,经检测质膜纯度较高 ,原位膜约占 78%。质膜 ATPase的动力学常数 Km 和 Vmax分别为0 5 8mmol L和 4 3 5 9μmol Pi ( mg protein· h) ;最适 p H值是 7 5。质膜 ATPase的活性随Mg Cl2 和 Ca Cl2 浓度的升高而增加 ,但较高浓度的 Mg Cl2 和 Ca Cl2 有轻微的抑制作用 ;KCl促进质膜 ATPase的活性 ,在 1 0 0 mmol L时达到最大 ,高于 1 0 0 mmol L时抑制效应显著。钒酸钠、DES、DCCD和 NEM明显地抑制质膜 ATPase的活性 ;而 Na N3、Na NO3、Na Mo O4和KCN对质膜 ATPase的活性影响不大。高渗震动刺激了质膜 ATPase的活性。
A fraction enriched in plasma membrane from Dunaliella salina was obtained by apueous two phase partition system (dextran T500/polyethylene glycol 3350),with high quality and purity.The K m of plasmalemma ATPase was found to be 0.58 mmol/L,its V max was 43.59 μmol Pi/(mg protein·h) and the optimum pH 7.5.Enzyme activity was stimulated by the increase of concentration of MgCl 2,CaCl 2 and KCl,but much higher concentrations had a little inhibitory effect.The plasmalemma ATPase exhibited great sensitivities to vanadate,dicyeclohexyl carbodiimide (DCCD),SH regent N ethylmaleimide (NEM),especially to diethylstibestro (DES),whereas it was insensitive to azide,nitrate,molybdate and cyanide.The ATPase activity was notably increased following hyperosmotic shock,and its possible role in osmoregulation was discussed.
出处
《武汉植物学研究》
CSCD
1999年第1期10-14,共5页
Journal of Wuhan Botanical Research
基金
蔡火石生物科学发展基金
关键词
盐生杜氏藻
质膜ATPase
高渗震动
Dunaliella salina, Characterization of plasmalemma ATPase, Hyperosmotic shock