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LaaA, a novel high-active alkalophilic alpha-amylase from deep-sea bacterium Luteimonas abyssi XH031T
被引：11
作者：
Song, Qinghao
[1
]
Wang, Yan
[1
]
Yin, Chong
[1
]
Zhang, Xiao-Hua
[1
]
机构：
[1] Ocean Univ China, Coll Marine Life Sci, Qingdao 266003, Peoples R China
基金：
中国国家自然科学基金;
关键词：
Alkalophilic alpha-amylase;
High-active;
Luteimonas abyssi;
Site-specific mutagenesis;
ALKALIPHILIC BACILLUS ISOLATE;
CRYSTAL-STRUCTURE;
CYCLODEXTRIN GLYCOSYLTRANSFERASE;
NUCLEOTIDE-SEQUENCE;
ALKALINE ADAPTATION;
SALT BRIDGE;
PURIFICATION;
GENE;
BINDING;
CLONING;
D O I：
10.1016/j.enzmictec.2016.05.003
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：
Alpha-amylase is a kind of broadly used industrial enzymes, most of which have been exploited from terrestrial organism. Comparatively, alpha-amylase from marine environment was largely undeveloped. In this study, a novel alkalophilic alpha-amylase with high activity, Luteimonas abyssi alpha-amylase (LaaA), was cloned from deep-sea bacterium L abyssi XH031(T) and expressed in Escherichia coli BL21. The gene has a length of 1428 bp and encodes 475 amino acids with a 35-residue signal peptide. The specific activity of LaaA reached 8881 U/mg at the optimum pH 9.0, which is obvious higher than other reported alpha-amylase. This enzyme can remain active at pH levels ranging from 6.0 to 11.0 and temperatures below 45 degrees C, retaining high activity even at low temperatures (almost 38% residual activity at 10 C). In addition, 1 mM Na+, K+, and Mn2+ enhanced the activity of LaaA. To investigate the function of potential active sites, R227G, D229K, E256Q/H, H327V and D328V mutants were generated, and the results suggested that Arg227, Asp229, Glu256 and Asp328 were total conserved and essential for the activity of alpha-amylase LaaA. This study shows that the alpha-amylase LaaA is an alkali-tolerant and high-active amylase with strong potential for use in detergent industry. (C) 2016 Elsevier Inc. All rights reserved.
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页码：83 / 92
页数：10
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