THERMOSTABLE LIQUEFYING ALPHA-AMYLASE FROM BACILLUS-AMYLOLIQUEFACIENS

被引：8
|
作者：
KOCHHAR, S
DUA, RD
机构：
[1] Biochemistry Laboratories, Indian Institute of Technology, New Delhi, 110 016, Hauz-Khas
来源：
BIOTECHNOLOGY LETTERS | 1990年 / 12卷 / 05期
关键词：
D O I：
10.1007/BF01024438
中图分类号：
Q81 [生物工程学（生物技术）]; Q93 [微生物学];
学科分类号：
071005 ; 0836 ; 090102 ; 100705 ;
摘要：
An extracellular α-amylase is purified to homogeneity with 62 % recovery of the enzyme activity using heat treatment, ion-exchange and gel filtration chromatographies. The purified enzyme has a molecular weight of 68, 000, isoelectric point 6.25, optimal activity at pH 6 and temperature 65 °C, kest 8.8×108 s1 liquefying amylase units, and Km for starch 2.9 mg ml-1. The enzyme is further characterized for its endo action on the starch and related polymers. Calcium stabilizes the active conformation of the enzyme during prolonged exposure to the extremes of pH and temperature. The enzyme retains 100 % activity for 24 h at 65°C and exhibits a half-life of 9, 3, and 0.5 h at 80°, 85° and 90°C, respectively. © 1990 Kluwer Academic Publishers.
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页码：393 / 396
页数：4
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