Deciphering the synergism of endogenous glycoside hydrolase families 1 and 9 from Coptotermes gestroi

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Termites can degrade up to 90% of the lignocellulose they ingest using a repertoire of endogenous and symbiotic degrading enzymes. Termites have been shown to secrete two main glycoside hydrolases, which are GH1 (EC 3.2.1.21) and GH9 (EC 3.2.1.4) members. However, the molecular mechanism for lignocellulose degradation by these enzymes remains poorly understood. The present study was conducted to understand the synergistic relationship between GH9 (CgEG1) and GH1 (CgBG1) from Coptotermes gestroi, which is considered the major urban pest of Sao Paulo State in Brazil. The goal of this work was to decipher the mode of operation of CgEG1 and CgBG1 through a comprehensive biochemical analysis and molecular docking studies. There was outstanding degree of synergy in degrading glucose polymers for the production of glucose as a result of the endo-beta-1,4-glucosidase and exo-beta-1,4-glucosidase degradation capability of CgEG1 in concert with the high catalytic performance of CgBG1, which rapidly converts the oligomers into glucose. Our data not only provide an increased comprehension regarding the synergistic mechanism of these two enzymes for cellulose saccharification but also give insight about the role of these two enzymes in termite biology, which can provide the foundation for the development of a number of important applied research topics, such as the control of termites as pests as well as the development of technologies for lignocellulose-to-bioproduct applications. (c) 2013 Elsevier Ltd. All rights reserved.4310970981Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)CNPq [474022/2011-4, 310177/2011-1]FAPESP [2008/58037-9, 2010/11469-1, 2011/13242-7, FAPESP 12/19040-0, 2011/20977-3, 2011/08609-9

Expression of Two Novel β-Glucosidases from Chaetomium atrobrunneum in Trichoderma reesei and Characterization of the Heterologous Protein Products

Two novel GH3 family thermostable β-glucosidases from the filamentous fungus Chaetomium atrobrunneum (CEL3a and CEL3b) were expressed in Trichoderma reesei, purified by two-step ion exchange chromatography, and characterized. Both enzymes were active over a wide range of pH as compared to Neurospora crassa β-glucosidase GH3-3, which was also expressed in T. reesei and purified. The optimum temperature of both C. atrobrunneum enzymes was around 60 °C at pH 5, and both enzymes had better thermal and pH stability and higher resistance to metallic compounds and to glucose inhibition than GH3-3. They also showed higher activity against oligosaccharides composed of glucose units and linked with β-1,4-glycosidic bonds and moreover, had higher affinity for cellotriose over cellobiose. In hydrolysis tests against Avicel cellulose and steam-exploded sugarcane bagasse, performed at 45 °C, particularly the CEL3a enzyme performed similarly to N. crassa GH3-3 β-glucosidase. Taking into account the thermal stability of the C. atrobrunneum β-glucosidases, they both represent promising alternatives as enzyme mixture components for improved cellulose saccharification at elevated temperatures

Stricture following gastric bypass and vertical sleeve gastrectomy

SCOPUS: ch.binfo:eu-repo/semantics/publishe