大麦芽极限糊精酶的分离纯化及酶学特性分析  

Purification and Enzymatic Characterization of Limit Dextrinase from Malted Barley

作　　者：彭雅莉[1] 胡飞[1] 

机构地区：[1]华南理工大学轻工与食品学院,广东广州510640

出　　处：《食品科学》2012年第1期204-208,共5页Food Science

基　　金：广东省科技计划项目(2007A020100001-12)

摘　　要：将大麦芽提取的极限糊精酶粗酶液,利用硫酸铵沉淀、离子交换层析和凝胶过滤色谱等分离方法对极限糊精酶进行逐步分离纯化。结果表明:纯化倍数为31.23,回收率为8.81%。经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳后,图谱显示样品具有较高的纯度,分子质量约为97kD。同时研究了纯化前后极限糊精酶在不同作用环境下酶的活性变化,发现纯化后样品在温度45℃和pH 5.5左右具有最大酶活性,与粗酶液中酶活性相比具有明显差异。在体系中添加不同浓度的金属离子,结果发现,Mg2+、Ca2+、Mn2+在浓度较低时,对酶活性具有激活作用,而浓度较高时,则具有抑制作用;整体上,K+对酶活性影响不大;Zn2+、Fe2+对酶活性具有抑制作用。This study was carried out to separate and purify limit dextrinase from malted barley by（NH4）2SO4 salting out,DEAE Sepharose FF column chromatography and Sephadex G-100 column chromatography.A purification fold of 31.23 and a recovery of 8.81% were achieved.The SDS-PAGE pattern of the purified limit dextrinase revealed a single band of protein（97 kD）.The effects of temperature and pH on limit dextrinase in both the crude extract and purified sample were studied.The results indicated that maximum activity of the purified limit dextrinase was observed under the conditions of 45 ℃ and pH 5.5 and showed an obvious difference as compared with the crude enzyme extract.Moreover,Mg2＋,Ca2＋ and Mn2＋ increased the activity of the enzyme at low concentrations,whereas Zn2＋ and Fe2＋ inhibited the activity at high concentrations.K＋ did not exhibit any effects on the activity of the enzyme.

关 键 词：极限糊精酶 纯化 酶特性 

分 类 号：TS201.2[轻工技术与工程—食品科学]