Critical factors to high thermostability of an alpha-amylase from hyperthermophilic archaeon Thermococcus onnurineus NA1 SCIE SCOPUS KCI

Cited 22 time in WEB OF SCIENCE Cited 24 time in Scopus
Title
Critical factors to high thermostability of an alpha-amylase from hyperthermophilic archaeon Thermococcus onnurineus NA1
Author(s)
Lim, Jae Kyu; Lee, Hyun Sook; Kim, Yun Jae; Bae, Seung Seob; Jeon, Jeong Ho; Kang, Sung Gyun; Lee, Jung-Hyun
KIOST Author(s)
Lee, Hyun Sook(이현숙)Kang, Sung Gyun(강성균)Lee, Jung Hyun(이정현)
Publication Year
2007-08
Abstract
Genomic analysis of a hyperthermophilic archaeon, Thermococcus onnurineus NA 1 [1], revealed the presence of an open reading frame consisting of 1,377 bp similar to alpha-amylases from Thermococcales, encoding a 458-residue polypeptide containing a putative 25-residue signal peptide. The mature form of the a-amylase was cloned and the recombinant enzyme was characterized. The optimum activity of the enzyme occurred at 80 degrees C and pH 5.5. The enzyme showed a liquefying activity, hydrolyzing maltooligosaccharides, amylopectin, and starch to produce mainly maltose (G2) to maltoheptaose (G7), but not pullulan and cyclodextrin. Surprisingly, the enzyme was not highly thermostable, with half-life (t(1/2)) values of 10 min at 90 degrees T, despite the high similarity to a-amylases from Pyrococcus. Factors affecting the thermostability were considered to enhance the thermostability. The presence of Ca2+ seemed to be critical, significantly changing t(1/2) at 90 degrees T to 153 min by the addition of 0.5 mM Ca2+. On the other hand, the thermostability was not enhanced by the addition of Zn2+ or other divalent metals, irrespective of the concentration. The mutagenetic study showed that the recovery of zinc-binding residues (His175 and Cys189) enhanced the thermostability, indicating that the residues involved in metal binding is very critical for the thermostability.
ISSN
1017-7825
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/4665
Bibliographic Citation
JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY, v.17, no.8, pp.1242 - 1248, 2007
Publisher
KOREAN SOC MICROBIOLOGY & BIOTECHNOLOGY
Subject
PYROCOCCUS-FURIOSUS; AMYLOLYTIC ENZYMES; BIOCHEMICAL-CHARACTERIZATION; SACCHAROMYCES-CEREVISIAE; RECOMBINANT ENZYME; EXPRESSION; CLONING; GENE; PURIFICATION; PROFUNDUS
Keywords
genomic analysis; hyperthen-nophile; cloning and expression; alpha-amylase
Type
Article
Language
English
Document Type
Article
Publisher
KOREAN SOC MICROBIOLOGY & BIOTECHNOLOGY
Related Researcher
Research Interests

marine biotechnology,molecular microbiology,해양생명공학,분자미생물학

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