Nakada T, Ikegami S, Chaen H, Kubota M, Fukuda S, Sugimoto T, Kurimoto M, Tsujisaka Y
Hayashibara Biochemical Laboratories, Inc., Okayama, Japan.
Biosci Biotechnol Biochem. 1996 Feb;60(2):263-6. doi: 10.1271/bbb.60.263.
A thermostable maltooligosyl trehalose synthase was purified from a cell-free extract of the thermoacidophilic archaebacterium Sulfolobus acidocaldarius ATCC 33909 to an electrophoretically homogeneous state by successive column chromatography on Sepabeads FP-DA13, Butyl-Toyopearl 650M, DEAE-Toyopearl 650S, Ultrogel AcA44, and Mono Q. The enzyme had a molecular mass of 74,000 by SDS-polyacrylamide gel electrophoresis and a pI of 5.9 by gel isoelectrofocusing. The N-terminal amino acid of the enzyme was methionine. The enzyme showed the highest activity from pH 5.0 to 5.5 and at 75 degrees C, and was stable from pH 4.5 to 9.5 and up to 85 degrees C. The enzyme activity was inhibited by Hg2+ and Cu2+. The Kms of the enzyme for maltotetraose, maltopentaose, maltohexaose, maltoheptaose, and short chain amylose (DP 18) were 41.5 mM, 7.1 mM, 5.7 mM, 1.4 mM, and 0.6 mM, respectively.
通过在Sepabeads FP - DA13、丁基 - Toyopearl 650M、DEAE - Toyopearl 650S、Ultrogel AcA44和Mono Q上连续进行柱色谱，从嗜热嗜酸古生菌嗜酸热硫化叶菌ATCC 33909的无细胞提取物中纯化出一种热稳定的麦芽寡糖海藻糖合酶，使其达到电泳纯状态。通过SDS - 聚丙烯酰胺凝胶电泳测定该酶的分子量为74,000，通过凝胶等电聚焦测定其pI为5.9。该酶的N端氨基酸为甲硫氨酸。该酶在pH 5.0至5.5以及75℃时表现出最高活性，在pH 4.5至9.5以及高达85℃时稳定。该酶的活性受到Hg2 +和Cu2 +的抑制。该酶对麦芽四糖、麦芽五糖、麦芽六糖、麦芽七糖和短链直链淀粉（DP 18）的Km值分别为41.5 mM、7.1 mM、5.7 mM、1.4 mM和0.6 mM。
