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.
作者
李蕊伽
廖海君
白亚娟
陶敏
唐菁
唐云明
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)
出处
《西南师范大学学报（自然科学版）》
CAS
北大核心
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)
关键词
芦荟叶皮
Β-葡萄糖苷酶
分离纯化
酶学性质
leaf skin of Aloe vera
β-Glucosidase
isolation and purification
enzymatic properties
