黑曲霉（同宇佐美曲霉）NRRL 3135中糖化酶的鉴定、特性分析及部分纯化

Identification, characterization, and partial purification of glucoamylase from Aspergillus niger (syn A. ficuum) NRRL 3135.

作者信息

Vandersall A S, Cameron R G, Nairn C J, Yelenosky G, Wodzinski R J

机构信息

Department of Molecular Biology and Microbiology, University of Central Florida, Orlando 32816, USA.

出版信息

Prep Biochem. 1995 Feb-May;25(1-2):29-55. doi: 10.1080/10826069508010106.

DOI:10.1080/10826069508010106

PMID:7603971

Abstract

The crude extracellular extract of Aspergillus niger (syn A. ficuum) NRRL 3135 contains glucoamylase (exo-1,4-alpha-D-glucanohydrolase, EC 3.2.1.2). The enzyme, a glycoprotein, was purified 7-fold by ion-exchange chromatography, chromatofocusing, and conconavalin A affinity chromatography. The molecular weight of the enzyme was estimated to be 90 kDa by SDS-PAGE and gel permeation chromatography. The pI of the enzyme was 3.4. The temperature optimum of the enzyme was 60 degrees C and the pH optimum was 5.0. The Vmax values for soluble starch, maltose, maltotriose, maltotretraose, maltopentaose, and isomaltose were 55.2, 11.7, 32.3, 47.8, 59.2, 12.5 nKat glucose/sec, respectively and the Km values for the same substrates were 0.09%, 0.67 mM, 0.76 mM, 0.76 mM, 0.68 mM, and 122.01 mM, respectively.

摘要

黑曲霉（同宇佐美曲霉）NRRL 3135的粗细胞外提取物含有葡糖淀粉酶（外切-1,4-α-D-葡聚糖水解酶，EC 3.2.1.2）。该酶为糖蛋白，通过离子交换色谱、色谱聚焦和伴刀豆球蛋白A亲和色谱纯化了7倍。通过SDS-PAGE和凝胶渗透色谱法估计该酶的分子量为90 kDa。该酶的pI为3.4。该酶的最适温度为60℃，最适pH为5.0。可溶性淀粉、麦芽糖、麦芽三糖、麦芽四糖、麦芽五糖和异麦芽糖的Vmax值分别为55.2、11.7、32.3、47.8、59.2、12.5 nKat葡萄糖/秒，相同底物的Km值分别为0.09%、0.67 mM、0.76 mM、0.76 mM、0.68 mM和122.01 mM。