{"title":"Stereochemistry of the hydrolysis of trehalose by the enzyme trehalase prepared from the flesh fly Sarcophaga barbata.","authors":"K. Clifford","doi":"10.1039/C39790000136","DOIUrl":null,"url":null,"abstract":"1. The enzyme trehalase was prepared from whole flesh flies, Sarcophaga barbata. 2. The rate of mutorotation of glucose released by the enzyme was compared with that of alpha-D-glucose, beta-D-glucose and an equimolar mixture of the two. 3. Derivatives of the glucose released by the enzyme were prepared and analysed by gas chromatography for anomeric composition. 4. The enzyme was incubated with trehalose in a medium enriched with H218O and the glucose was analysed by gas chromatography/mass spectrometry. 5. It was found that an equimolar mixture of alpha-D-glucose and beta-D-glucose is formed on hydrolysis of trehalose by trehalase and 18O is incorporated into beta-D-glucose. 6. These results indicate that there is an inversion of configuration at C-1 of trehalose on hydrolysis and that the hydrolysis proceeds by a bimolecular nucleophilic substitution mechanism.","PeriodicalId":11817,"journal":{"name":"European journal of biochemistry","volume":"20 1","pages":"337-40"},"PeriodicalIF":0.0000,"publicationDate":"2005-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"23","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European journal of biochemistry","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1039/C39790000136","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 23
Abstract
1. The enzyme trehalase was prepared from whole flesh flies, Sarcophaga barbata. 2. The rate of mutorotation of glucose released by the enzyme was compared with that of alpha-D-glucose, beta-D-glucose and an equimolar mixture of the two. 3. Derivatives of the glucose released by the enzyme were prepared and analysed by gas chromatography for anomeric composition. 4. The enzyme was incubated with trehalose in a medium enriched with H218O and the glucose was analysed by gas chromatography/mass spectrometry. 5. It was found that an equimolar mixture of alpha-D-glucose and beta-D-glucose is formed on hydrolysis of trehalose by trehalase and 18O is incorporated into beta-D-glucose. 6. These results indicate that there is an inversion of configuration at C-1 of trehalose on hydrolysis and that the hydrolysis proceeds by a bimolecular nucleophilic substitution mechanism.
1. 以全蝇(Sarcophaga barbata)为原料制备海藻酶。2. 将该酶释放的葡萄糖的变形速率与α - d -葡萄糖、β - d -葡萄糖以及两者的等摩尔混合物的变形速率进行了比较。3.制备了该酶释放的葡萄糖衍生物,并用气相色谱法对其进行了分析。4. 将酶与海藻糖在富含H218O的培养基中孵育,用气相色谱/质谱法分析葡萄糖。5. 发现海藻糖酶水解海藻糖形成α - d -葡萄糖和β - d -葡萄糖的等摩尔混合物,18O被纳入β - d -葡萄糖中。6. 这些结果表明海藻糖在水解过程中存在C-1位构型的反转,水解过程是通过双分子亲核取代机制进行的。