Streptomyces hygroscopicus谷氨酰胺转胺酶的分离纯化及其性质研究

Purification and Characterization of Transglutaminase from Streptomyces hygrosco

将新筛选的吸水链霉菌生产的谷氨酰胺转胺酶发酵液抽滤、盐析、离心和冷冻干燥,制得粗酶产品,酶的比活力为5 4 0U/ g ,收率为77 90 %。对粗酶的研究发现,在2 5～4 0℃、pH 6 0～8 0范围内,该酶都有较高的反应活性和稳定性。粗酶经离子交换层析后得到了较高的纯化,纯化倍数为13 1倍,收率6 3% ;再经凝胶过滤层析,酶纯化了1 14倍,收率6 5 % ;经SDS -PAGE电泳检测,得到了单一的区带,根据电泳标准分子量计算,该酶的相对分子质量约为38 32 4ku。

Transglutaminase was separated from the culture broth derived from a novel strain of Streptomyces hygroscopicus. The crude enzyme was obtained by filtration, precipitation by (NH 4) 2SO 4, centrifugation and freeze-drying. The specific activity of the crude enzyme was 540 U/g, and the yield was 77.90%. It was found that Transglutaminase had high activity and good stability at 25～40℃ and pH6.0～8.0.The crude enzyme was further purified 13.1 fold by CM-cellulose and 1.14 fold by Superdex 75 chromatography with the yield of 63% and 65% respectively. The Transglutaminase purified in this study had one band on SDS-PAGE with the molecular weight of 38.324 ku.