Separation, Characterization, and Specificity of α-Mannosidases from Vigna umbellata

Information about the specificity of glycosidase enzymes is important since it affects their use for characterization and synthesis of oligosaccharides. Two α-mannosidases (EC 3.2.1.24), I and II, were isolated from rice beans (Vigna umbellata). The native molecular weight of both isozymes was estim...

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Bibliographic Details
Main Authors: Patjaraporn Wongvithoonyaporn, Christopher Bucke, Jisnuson Svasti
Other Authors: Mahidol University
Format: Article
Published: 2018
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Online Access:https://repository.li.mahidol.ac.th/handle/123456789/18328
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Institution: Mahidol University
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Summary:Information about the specificity of glycosidase enzymes is important since it affects their use for characterization and synthesis of oligosaccharides. Two α-mannosidases (EC 3.2.1.24), I and II, were isolated from rice beans (Vigna umbellata). The native molecular weight of both isozymes was estimated to be 329,000, but pIs of form I were 5.03-5.34 and pIs of form II were 5.46-6.20. The two isozymes were characterized in terms of optimal pH and temperature, effects of metal ions, inhibition by swainsonine and 1-deoxymannojirimycin, and kinetic parameters for p-nitrophenyl-α-D-mannopyranoside and Manα(1-2)Man. Both enzymes were more specific towards Manα(1-2)Man in both hydrolysis and synthesis, but their hydrolytic specificities towards Manα(1-3)[Manα(1-6)]Man were different. © 1998, Taylor & Francis Group, LLC. All rights reserved.