金担子菌葡糖基转移酶的纯化及性质

Purification and properties of glucosyltransferase from Aureobasidium.

作者信息

Hayashi S, Hayashi T, Takasaki Y, Imada K

机构信息

Department of Materials Science, Faculty of Engineering, Miyazaki University, Japan.

出版信息

J Ind Microbiol. 1994 Jan;13(1):5-9. doi: 10.1007/BF01569655.

DOI:10.1007/BF01569655

PMID:7764553

Abstract

Purification and properties of glucosyltransferase, which produces panose (Glc alpha 1-->6Glc alpha 1-->4Glc) and isomaltose (Glc alpha 1-->6Glc) from maltose (Glc alpha 1-->4Glc), are reported. The enzyme, from Aureobasidium, was purified to homogeneity by fractionations involving ammonium sulfate and DEAE-Cellulofine, S-Sepharose Fast Flow and Sephadex G-200 chromatography. Molecular mass of the enzyme was estimated to be 395 kDa by gel filtration. The enzyme was identified as a glycoprotein which contains 32% (w/w) carbohydrate. The optimum pH for the enzymatic reaction was 4.5-5.5 and the enzyme was stable over a pH range of 4-6. The optimum reaction temperature for the enzyme was 65 degrees C and the enzyme retained more than 96% activity at 60 degrees C after 15 min. The enzyme produced panose from maltose by means of a high efficiency (45.5%) glucosyl-transfer reaction. The enzyme was inhibited by metal ions, such as those of mercury, silver and aluminum, and also by organic inhibitors, especially nitrilotriacetic acid.

摘要

报道了一种葡糖基转移酶的纯化及性质，该酶可由麦芽糖（Glcα1→4Glc）生成潘糖（Glcα1→6Glcα1→4Glc）和异麦芽糖（Glcα1→6Glc）。来自 Aureobasidium 的这种酶通过硫酸铵分级沉淀以及 DEAE - 纤维素、S - 琼脂糖快速流动柱和葡聚糖 G - 200 柱层析等步骤纯化至同质。通过凝胶过滤法估计该酶的分子量为 395 kDa。该酶被鉴定为一种糖蛋白，其碳水化合物含量为 32%（w/w）。酶促反应的最适 pH 为 4.5 - 5.5，且该酶在 pH 4 - 6 的范围内稳定。该酶的最适反应温度为 65℃，在 60℃保温 15 分钟后仍保留超过 96%的活性。该酶通过高效（45.5%）的葡糖基转移反应由麦芽糖生成潘糖。该酶受到汞、银和铝等金属离子以及有机抑制剂（尤其是次氮基三乙酸）的抑制。