Characterization and Kinetics of 45 kDa Chitosanase fromBacillussp. P16
| Autor: | Yong-Woong Kim, Jae-Han Shim, You-Young Jo, Yu-Lan Jin, Ro-Dong Park, Kyu-Jong Jo, Kil-Yong Kim |
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| Rok vydání: | 2003 |
| Předmět: |
Glycoside Hydrolases
Starch Oligosaccharides Bacillus Chitin Polysaccharide Applied Microbiology and Biotechnology Biochemistry Analytical Chemistry Chitosan Hydrolysis chemistry.chemical_compound Polysaccharides Enzyme Stability Chitosanase Cellulose Molecular Biology chemistry.chemical_classification Chromatography biology Viscosity Organic Chemistry Temperature Acetylation General Medicine Hydrogen-Ion Concentration Enzyme assay Molecular Weight carbohydrates (lipids) Kinetics chemistry Solvents biology.protein Electrophoresis Polyacrylamide Gel Salts Chromatography Thin Layer Biotechnology |
| Zdroj: | Bioscience, Biotechnology, and Biochemistry. 67:1875-1882 |
| ISSN: | 1347-6947 0916-8451 |
| DOI: | 10.1271/bbb.67.1875 |
| Popis: | An extracellular 45 kDa endochitosanase was purified and characterized from the culture supernatant of Bacillus sp. P16. The purified enzyme showed an optimum pH of 5.5 and optimum temperature of 60 degrees C, and was stable between pH 4.5-10.0 and under 50 degrees C. The Km and Vmax were measured with a chitosan of a D.A. of 20.2% as 0.52 mg/ml and 7.71 x 10(-6) mol/sec/mg protein, respectively. The enzyme did not degrade chitin, cellulose, or starch. The chitosanase digested partially N-acetylated chitosans, with maximum activity for 15-30% and lesser activity for 0-15% acetylated chitosan. The chitosanase rapidly reduced the viscosity of chitosan solutions at a very early stage of reaction, suggesting the endotype of cleavage in polymeric chitosan chains. The chitosanase hydrolyzed (GlcN)7 in an endo-splitting manner producing a mixture of (GlcN)(2-5). Time course studies showed a decrease in the rate of substrate degradation from (GlcN)7 to (GlcN)6 to (GlcN)5, as indicated by the apparent first order rate constants, k1 values, of 4.98 x 10(-4), 2.3 x 10(-4), and 9.3 x 10(-6) sec(-1), respectively. The enzyme hardly catalyzed degradation of chitooligomers smaller than the pentamer. |
| Databáze: | OpenAIRE |
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