GH43 endo-arabinanase from Bacillus licheniformis: Structure, activity and unexpected synergistic effect on cellulose enzymatic hydrolysis

Author(s)

Farro, Erick Giancarlo S. ^[1] ; Leite, Ana Elisa T. ^[1] ; Silva, Isabela A. ^[1] ; Filgueiras, Jefferson G. ^[1] ; de Azevedo, Eduardo R. ^[1] ; Polikarpov, Igor ^[1] ; Nascimento, Alessandro S. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Fis Sao Carlos, Av Trabalhador Sao Carlense 400, BR-13566590 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: International Journal of Biological Macromolecules; v. 117, p. 7-16, OCT 1 2018.
• Web of Science Citations: 2

Abstract

The hydrolysis of the plant biomass provides many interesting opportunities for the generation of building blocks for the green chemistry industrial applications. An important progress has been made for the hydrolysis of the cellulosic component of the biomass while, for the hemicellulosic components, the advances are less straightforward. Here, we describe the cloning, expression and biochemical and structural characterization of BlAbnl, a GH43 arabinanase from Bacillus licheniformis. This enzyme is selective for linear arabinan and efficiently hydrolyzes this substrate, with a specific activity of 127 U/mg. The enzyme has optimal conditions for activity at pH 8.0 and 45 degrees C and its activity is only partially dependent of a bound calcium ion since 70% of the maximal activity is preserved even when 1 mM EDTA is added to the reaction medium. BlAbn1 crystal structure revealed a typical GH43 fold and narrow active site, which explains the selectivity for linear substrates. Unexpectedly, the enzyme showed a synergic effect with the commercial cocktail Accellerase 1500 on cellulose hydrolysis. Scanning Electron Microscopy, Solid-State NMR and relaxometry data indicate that the enzyme weakens the interaction between cellulose fibers in filter paper, thus providing an increased access to the cellulases of the cocktail. (C) 2018 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 14/06565-2 - Extending the frontiers in biomolecular interactions: docking and free energy assessment
• Grantee: Alessandro Silva Nascimento
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/13684-0 - Structural and functional studies of enzymes that participate in complex carbohydrates synthesis and degradation
• Grantee: Igor Polikarpov
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 14/03768-0 - Search for structural templates for the engineering of catalytic functions
• Grantee: Erick Giancarlo Suclupe Farro
• Support Opportunities: Scholarships in Brazil - Master