Biochemical Characterization and Low-Resolution SAXS Molecular Envelope of GH1 beta-Glycosidase from Saccharophagus degradans

Author(s)

Brognaro, Hevila ; Almeida, Vitor Medeiros ; de Araujo, Evandro Ares ; Piyadov, Vasily ; Morim Santos, Maria Auxiliadora ; Marana, Sandro Roberto ; Polikarpov, Igor

• Document type: Journal article
• Source: MOLECULAR BIOTECHNOLOGY; v. 58, n. 12, p. 777-788, DEC 2016.
• Web of Science Citations: 1

Abstract

The marine bacteria Saccharophagus degradans (also known as Microbulbifer degradans), are rod-shaped and gram-negative motile gamma-proteobacteria, capable of both degrading a variety of complex polysaccharides and fermenting monosaccharides into ethanol. In order to obtain insights into structure-function relationships of the enzymes, involved in these biochemical processes, we characterized a S. degradans beta-glycosidase from glycoside hydrolase family 1 (SdBgl1B). SdBgl1B has the optimum pH of 6.0 and a melting temperature T-m of approximately 50 degrees C. The enzyme has high specificity toward short D-glucose saccharides with beta-linkages with the following preferences beta-1,3 > beta-1,4 << beta-1,6. The enzyme kinetic parameters, obtained using artificial substrates p-beta-NPGlu and p-beta-NPFuc and also the disaccharides cellobiose, gentiobiose and laminaribiose, revealed SdBgl1B preference for p-beta-NPGlu and laminaribiose, which indicates its affinity for glucose and also preference for beta-1,3 linkages. To better understand structural basis of the enzyme activity its 3D model was built and analysed. The 3D model fits well into the experimentally retrieved low-resolution SAXS-based envelope of the enzyme, confirming monomeric state of SdBgl1B in solution. (AU)

• FAPESP's process: 08/56255-9 - Structure and function of enzymes and auxiliary proteins from Trichoderma, active in cell-wall hydrolysis
• Grantee: Igor Polikarpov
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Thematic Grants