標題: | Catalytic function of a newly purified exo-beta-D-glucosaminidase from the entomopathogenic fungus Paecilomyces lilacinus |
作者: | Chao, Cheng-Fu Chen, Yi-Yun Cheng, Chih-Yu Li, Yaw-Kuen 應用化學系 Department of Applied Chemistry |
關鍵字: | Glycohydrolase;Exo-beta-D-glucosaminidase;Transglycosylation;Mass spectrometry;GlcN-GlcNAc-butyl;Paecilomyces lilacinus |
公開日期: | 2-四月-2013 |
摘要: | An entomopathogenic fungus, Paecilomyces lilacinus, was found to grow on chitosanase-detecting plates. Besides an endo-chitosanase, an exo-beta-D-glucosaminidase was purified by cation-exchange chromatography from this microorganism cultivated in M9 minimal media containing 0.5% chitosan as the sole carbon source. The molecular weight of the enzyme is 95 kDa; the optimum pH and temperature for activity are 6.0 and 45 degrees C, respectively. The purified exo-beta-D-GlcNase promotes the hydrolysis of 95% deacetylated chitosan from its non-reducing end and liberates 2-amino-2-deoxy-D-glucopyranose (GlcN) as the sole product; however, 2-acetamido-2-deoxy-D-glucopyranose (GlcNAc) was not detected when chitin was used as the substrate. The cleavage pattern confirmed using real-time mass spectrometry shows that exo-beta-D-glucosaminidase cleaves the glycosidic bonds between GlcN-GlcN and GlcN-GlcNAc but not between GlcNAc-GlcN or GlcNAc-GlcNAc. In the presence of a 10% solution of various alcohols, many alkyl-beta-D-glucosaminides were obtained, indicating that exo-beta-D-glucosaminidase is a retaining enzyme. (c) 2012 Elsevier Ltd. All rights reserved. |
URI: | http://dx.doi.org/10.1016/j.carbpol.2012.12.030 http://hdl.handle.net/11536/21678 |
ISSN: | 0144-8617 |
DOI: | 10.1016/j.carbpol.2012.12.030 |
期刊: | CARBOHYDRATE POLYMERS |
Volume: | 93 |
Issue: | 2 |
起始頁: | 615 |
結束頁: | 621 |
顯示於類別: | 期刊論文 |