Purification and characterization of a chitinase from Serratia proteamaculans
| Autor: | Muhammad Aamer Mehmood, Fauzia Yusuf Hafeez, Fengping Wang, Yingbao Gai, Xiang Xiao |
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| Rok vydání: | 2009 |
| Předmět: |
Hyphal growth
biology Physiology Aspergillus niger General Medicine biology.organism_classification Applied Microbiology and Biotechnology Serratia proteamaculans Enzyme assay chemistry.chemical_compound Isoelectric point Chitin chemistry Affinity chromatography Biochemistry Chitinase biology.protein Biotechnology |
| Zdroj: | World Journal of Microbiology and Biotechnology. 25:1955-1961 |
| ISSN: | 1573-0972 0959-3993 |
| DOI: | 10.1007/s11274-009-0094-3 |
| Popis: | A chitinase gene from Serratia proteamaculans 18A1 was cloned, sequenced, and expressed in Escherichia coli M15. Recombinant enzyme (ChiA) was purified by Ni-NTA affinity column chromatography. The ChiA gene contains an open reading frame (ORF), encoding an endochitinase with a deduced molecular weight 60 kDa and predicted isoelectric point of 6.35. Comparison of ChiA with other chitinases revealed a modular structure containing an N-terminal PKD-domain, a family 18 catalytic domain and a C-terminal putative chitin-binding domain. Turn over rate (K cat) of the enzyme was determined using colloidal chitin (49.71 ± 1.15 S−1) and crystalline β-chitin (17.20 ± 0.83 S−1) as substrates. The purified enzyme was active over a broad range of pH (pH 4.5–9.0) and temperature (4–70°C) with a peak activity at pH 5.5 and 55°C. However, enzyme activity was found to be stable up to 45°C for longer incubation periods. Purified enzyme was shown to inhibit fungal spore germination and hyphal growth of pathogenic fungi Fusarium oxysporum and Aspergillus niger. |
| Databáze: | OpenAIRE |
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