Functional and structural studies of enzyme class endoglucanases GHF45 aiming for application in biomass hydrolysis

• Grant number: 11/19100-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: May 01, 2012
• End date: September 30, 2015
• Field of knowledge: Biological Sciences - Biophysics - Molecular Biophysics
• Principal Investigator: Igor Polikarpov
• Grantee: Marina Paglione Ramia
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 08/56255-9 - Structure and function of enzymes and auxiliary proteins from Trichoderma, active in cell-wall hydrolysis, AP.BIOEN.TEM

Abstract

Glycosyl hydrolases are a widespread group of enzymes which hydrolyse the glycosidic bond between two or more carbohydrates or between a carbohydrate and a non-carbohydrate moiety. There are 125 families of glycosyl hydrolases, which the most cases has the mechanism of action of glycosidic bond hydrolysis catalyzed by two amino acid residues of the enzyme: a general acid and a nucleophile. Depending on the spatial position of catalytic residues, the hydrolysis occurs with overall retention or inversion of the general anomeric configuration. Cellulases are distinguished from other glycoside hydrolases by hydrolyzing the 1,4 connections, between glucose residues. The hydrolysis of cellulose resulting in glucose monomers is performed by enzymatic systems that generally include three types of enzymes that differ based on mode of catalysis of cellulose, but act synergistically: endo-1,4-glucanase, exo-1,4-glucanase or celobiohidrolase and celobiase or beta-glucosidase. The endo-glucanases attack the amorphous part of cellulose by cleaving the internal microfibrils, decreasing the size of the chain, generating oligosaccharides of different sizes and new free ends, water and forming celooligossacarídeos to be hydrolyzed cellobiose and glucose. The family 45 of glycosyl hydrolases uses the reaction of inversion as a mechanism of hydrolysis. These enzymes share a small catalytic domain (20 kDa) and a variety of substrates such as cellulose and its derivatives. They has been well characterized from the functional point of view, however, few structures have been solved, which hinders the understanding of its mechanism of action. To remedy this shortcoming, it is proposed in this project the structural study of the endo-glucanases, so the knowledge of the behavior of microorganisms during the fermentation process, as well as its enzymatic activity, make possible the improvement of methods, the optimization; modification and control of biotechnological processes involving this class of enzymes. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

RAMIA, Marina Paglione. Structural and functional studies of an endoglucanase from Phanerochaete chrysorporium belonging to the glycoside hydrolase family 45. 2015. Doctoral Thesis - Universidade de São Paulo (USP). Instituto de Física de São Carlos (IFSC/BT) São Carlos.