两相分配法制备玉米根质膜及其纯度鉴定

用ＤｅｘｔｒａｎＴ５００，ＰＥＧ３３５０两相体系制备玉米根质膜．首先在高盐浓度（２２ｍｍｏｌ／ＬＮａＣｌ）下选用五种不同的聚合物浓度（５．８％、６．０％、６．２％、６．３％、６．４％，Ｗ／Ｗ），研究了玉米根质膜在两相体系中的分配情况，在此基础上进一步研究了Ｎａ－Ｃｌ浓度（２、４、５、１１、２２ｍｍｏｌ／Ｌ）对玉米根质膜的纯度及得率的影响．结果表明，制备玉米根质膜选用６．２％（Ｗ／Ｗ）聚合物浓度，７．５ｍｍｏｌ／ＬＮａＣｌ的两相体系比较合适．标志酶鉴定及低ｐＨ值磷钨酸染色电镜检测均表明获得了高纯度密实的正向型的质膜囊泡，质膜标志酶ＶＯ３－４－ＡＴＰａｓｅ的活性潜势达８８．９％．

Identification of Plasma Membrane of Maize Roots Prepared by Two phase Partition

Plasma membrane of maize roots was purified from the microsome in two phase aqueous system which is composed of Dextran T500 and PEG 3350.The effect of the concentration of polymer and salt on partition of plasma membrane in polymer system was studied.The result indicated that the system which consists of 6 2%(W/W) Dextran T500 and PEG 3350,7 5 mmol/L NaCl is suitable for maize roots plasma membrane.The electron micrograph stained with phosphotungstic acid and marker enzyme activities analysis proved that preparation has obtained high purity sealed right side out vesicles of plasma membrane,the latency of VO 3- 4 ATPase was up to 88 9%.