芦荟叶皮β-葡萄糖苷酶的分离纯化及酶学性质  

On Isolation,Purification and Characterization of β-Glucosidase from Leaf Skin of Aloe Vera

作　　者：李蕊伽[1] 廖海君 白亚娟[1] 陶敏[1] 唐菁[1] 唐云明[1] LI Rui-jia LIAO Hai-jun BAI Ya-juan TAO Min TANG Jing TANG Yun-ming(Key Laboratory of Eco-environments in Three Gorges Reservoir Region , Ministry of Education ,Chongqing Sweet Potato Engineering Research Center,School of Life Science,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学生命科学学院/重庆市甘薯工程研究中心/三峡库区生态环境教育部重点实验室,重庆400715

出　　处：《西南师范大学学报（自然科学版）》2017年第4期53-60,共8页Journal of Southwest China Normal University(Natural Science Edition)

基　　金：中央高校基本业务费专项资金资助(XDJK2016C110)

摘　　要：库拉索芦荟叶皮经匀浆、柠檬酸-柠檬酸钠缓冲液抽提,硫酸铵分级沉淀,DEAE-Sepharose fast flow层析和Superdex-200prep grade层析,获得电泳纯的β-葡萄糖苷酶(β-Glucosidase,BGL).纯化结果是β-葡萄糖苷酶比活力为98.48U/mg,纯化倍数为328.27倍,酶活性回收率为9.87%,全酶分子质量约为69.3kD,亚基分子质量约为69.7kD.酶学性质研究表明:β-葡萄糖苷酶的最适反应温度和最适反应pH值分别为40℃和5.0;在20~30℃及pH4.0~8.0范围内稳定性较好;最适条件下,以pNPG为底物的K_m值为2.21mmol/L,V_(max)为1.381μmol/(min·L).乙醇,抗坏血酸,Mn^(2+),K^+对该酶活性具有激活作用;SDS,Cu^(2+)对该酶活性具有强烈抑制作用;异丙醇,EDTA,尿素,Mg^(2+),Li+对该酶活性影响较小;甲醇对该酶有双重作用.Electrophoresis-purityβ-Glucosidase from leaf skin of Aloe vera has been obtained through homogenization,citrate buffer extraction,ammonium sulfate fractionation,DEAE-Sepharose fast flow chromatography and Superdex-200 prep grade chromatography.After purification,the result shows that the specific activity ofβ-Glucosidase is 98.48U/mg,with a 328.27-fold purification and a 9.87%activity recovery.The relative molecular weight of theβ-Glucosidase is approximately 69.3kD,in which the subunit molecular mass is roughly 69.7kD.The enzymatic properties illustrated that the optimum temperature and pH for theβ-Glucosidase are 40 ℃ and 5.0,respectively.This enzyme is stable at 20-30 ℃ and at pH4.0-8.0.Its apparent Kmand V（max）are 2.21mmol/L and 1.381μmol/（min·L）towards pNPG.The enzyme activity ofβ-Glucosidase could be activated by ethanol,ascorbic acid,Mn^（2＋）,K^＋,and strongly inhibited by SDS,Cu^（2＋）.Isopropanol,EDTA,urea,Mg^（2＋）,Li＋had little activation for it.Methanol has a dual effect on this enzyme.

关 键 词：芦荟叶皮 Β-葡萄糖苷酶 分离纯化 酶学性质 

分 类 号：Q946.5[生物学—植物学]