...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Acta Physiologiae Plantarum >Dioscorea opposita Thunb. alpha-mannosidase belongs to the glycosyl hydrolase family 38
【24h】

Dioscorea opposita Thunb. alpha-mannosidase belongs to the glycosyl hydrolase family 38

机译：薯对生。 α-甘露糖苷酶属于糖基水解酶家族38

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

alpha-Mannosidase (EC 3.2.1.24) was purified from 'Iseimo', a native variety of Dioscorea opposita Thunb. Before purification, we investigated the composition of a viscous polysaccharide that interferes with column chromatography procedures. The polysaccharide consisted mainly of mannose, and also contained uronic acid. We used the cationic detergent cetylpyridinium chloride (CPC) to remove the polysaccharide. CPC treatment decreased viscosity without affecting alpha-mannosidase activity. We purified alpha-mannosidase 2,650-fold. The optimal pH of the enzyme was 6.0 and the optimum temperature was 65A degrees C. The K (m) value for p-nitrophenyl-alpha-d-mannopyranoside was 0.35 +/- A 0.03 mM. Activity was inhibited by swainsonine but not kifunensine. The enzyme cleaved alpha-1,2 linkages preferentially to alpha-1,6 and alpha-1,3 linkages. The M (r) of purified alpha-mannosidase was estimated to be 250-260 kDa by gel filtration and native-PAGE. Four polypeptides (86, 83, 80, and 28 kDa) were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It is unclear whether the polypeptides are encoded by one gene or multiple genes. However, N-terminal sequence analysis suggested that post-translational cleavage and/or glycosylation resulted in the three large fragments, if these amino acids were encoded by the same gene. Homology searches and characterization of the enzyme's properties indicated that Iseimo alpha-mannosidase belongs to the glycoside hydrolase family 38 proteins, and to the Class II mannosidase group.
机译：α-甘露糖苷酶（EC 3.2.1.24）是从“ Iseimo”（Dioscorea opposita Thunb的天然变种）中纯化得到的。在纯化之前，我们研究了会干扰柱色谱程序的粘性多糖的组成。多糖主要由甘露糖组成，还含有糖醛酸。我们使用阳离子洗涤剂十六烷基吡啶鎓氯化物（CPC）去除了多糖。 CPC处理可降低粘度，而不会影响α-甘露糖苷酶活性。我们纯化了2,650倍的α-甘露糖苷酶。该酶的最适pH为6.0，最适温度为65℃。对硝基苯基-α-d-甘露吡喃糖苷的K（m）值为0.35 +/- A 0.03mM。 swainsonine抑制活性，而kifunensine则抑制活性。该酶优先切割α-1,1,2和α-1,6和α-1,3。通过凝胶过滤和天然PAGE估计纯化的α-甘露糖苷酶的M（r）为250-260kDa。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳检测到四种多肽（86、83、80和28 kDa）。尚不清楚多肽是由一个基因还是多个基因编码的。但是，N末端序列分析表明，如果这些氨基酸是由同一基因编码的，则翻译后的切割和/或糖基化会产生三个大片段。同源性搜索和酶性质的表征表明，Iseimoα-甘露糖苷酶属于糖苷水解酶家族38蛋白，属于II类甘露糖苷酶组。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号