玉米花粉低分子量ATP酶部分性质研究

对纯化的玉米花粉低分子量ＡＴＰ酶－３８ｋＤ蛋白的部分理化及药理学性质进行了研究。该酶与植物细胞中现已发现的马达蛋白（动蛋白及ｄｙｎａｍｉｎ）存在较大差异。紫外吸收光谱在２７８ｎｍ处有最大吸收。圆二色谱分析表明该蛋白呈现典型球蛋白特征。最适ｐＨ为８．０，对ＡＴＰ的Ｋｍ为８×１０－４ｍｏｌ／Ｌ，Ｖｍａｘ为３．５μｍｏｌＰｉ每ｍｉｎ每ｍｇ蛋白质。对ＮＴＰ底物专一性为ＣＴＰ＞ＡＴＰ≥ＧＴＰ＞ＩＴＰ＞ＵＴＰ，药理学研究表明：该酶对０．１ｍｍｏｌ／ＬＮａ３ＶＯ４、２．４ｍｍｏｌ／ＬＮａＦ及０．１ｍｍｏｌ／ＬＮＥＭ均非常敏感。

Some Properties of Low-molecular Weight ATPase from Maize Pollen

Some properties of the purified 38 kD ATPase were studied.CD spectrum analysis showed that the percentage ofα-heliex,β-sheet and random coil of the ATPase were 25.5%,18.8% and 55.5%.respectively,indicating the ATPase existed typical feature of globulin.It's maximum ultraviolet absorbance was found to be at 278 nm.The optimum pH of ATP hydrolysis was 8.0.The Km for ATP was found to be 8×10-4 mol/L and its Vmax was 3.5 μmol Pi per min per mg protein determined by Lineweaver-Burk plots.Analyzed results of substrate specificity showed:CTP>ATPM≥GTP>ITP>UIP.Pharmacological characterization showed that hydrolysis of the ATPase was strongly inhibited by Na,VO4.NEM and NaF.partly inhibited by ouabain,but not by oligomycin or KNO3 at the conentrations assayed.