Cloning, purification, and characterization of chitinase from Bacillus sp. DAU101.
A chitinase encoding gene from Bacillus sp. DAU101 was cloned in Escherichia coli. The nucleotide sequencing revealed a single open reading frame containing 1781 bp and encoding 597 amino acids with 66 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zymogram. The chitinase was composed of three domains: a catalytic domain, a fibronectin III domain, and a chitin binding domain. The chitinase was purified by GST-fusion purification system. The pH and temperature optima of the enzyme were 7.5 and 60 degrees C, respectively. The metal ions, Zn(2+), Cu(2+), and Hg(2+), were strongly inhibited chitinase activity. However, chitinase activity was increased 1.4-fold by Co(2+). Chisb could hydrolyze GlcNAc(2) to N-acetylglucosamine and was produced GlcNAc(2), when chitin derivatives were used as the substrate. This indicated that Chisb was a bifunctional enzyme, N-acetylglucosaminase and chitobiosidase. The enzyme could not hydrolyze glycol chitin, glycol chitosan, or CMC, but hydrolyzed colloidal chitin and soluble chitosan.
Lee
Yong-Seok
YS
Division of Biotechnology, Faculty of Natural Resources and Life Science, Dong-a University, Busan 604-714, Republic of Korea.
Park
In-Hye
IH
Yoo
Ju-Soon
JS
Chung
Soo-Yeol
SY
Lee
Young-Choon
YC
Cho
Young-Su
YS
Ahn
Soon-Cheol
SC
Kim
Cheol-Min
CM
Choi
Yong-Lark
YL
D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000032:analysis; D019677:Artificial Gene Fusion; D001407:Bacillus / Q000201:enzymology* / Q000235:genetics; D002412:Cations / Q000378:metabolism; D002688:Chitinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity; D013696:Temperature
D000935:Antifungal Agents; D002412:Cations; D002688:Chitinases