Functional analysis of disordered regions associated to lytic polysaccharide monooxygenases (LPMO): Biochemical characterization and interaction with cellobiose dehydrogenase (CDH)

• Grant number: 22/14376-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2023
• End date: February 29, 2024
• Field of knowledge: Biological Sciences - Biochemistry - Enzymology
• Principal Investigator: Fernando Segato
• Grantee: Gabriel de Almeida Fozzati
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil
• Associated research grant: 21/06679-1 - Enzymatic oxidation of sugarcane bagasse 2: exploring the interaction between LPMOs and its redox partner CDHs aiming for the development of more efficient enzymes for insertion into an engineered cell factory, AP.BIOEN.JP2
• Associated scholarship(s): 23/09421-0 - Functional analysis of C-terminal disordered regions (dCTRs) associated with lytic polysaccharide monooxygenases (LPMOs): biochemical characterization and assessment of potential roles in enzyme stability and electron transfer to the LPMO domain, BE.EP.IC

Abstract

LPMOs (Lytic Polysaccharide Monooxygenases) are metalloenzymes that depend on the presence of a copper atom in their active site, which needs to be reduced by an electron donor to initiate the catalysis process. Among the redox partners for LPMOs are several low molecular weight molecules (ascorbic acid, for example), photoactivated pigments, lignin or enzymes such as cellobiose dehydrogenase (CDH). Among the eight families of LPMOs, family 9 (AA9) has been one of the most studied, reaching its industrial application in enzymatic saccharification processes of lignocellulosic biomass, being part of the latest generation commercial enzymatic cocktails. However, there are still enigmatic aspects of these enzymes to be fully described, such as their catalytic mechanism, their natural co-substrate (O2 or H2O2) and the function of intrinsically disordered regions (IDRs), which were recently identified. IDRs are structures that appear with high frequency attached to the catalytic domains of LPMOs, being absent in other carbohydrate-active enzymes. During the research carried out by our group, an LPMO of the AA9 family containing an IDR (AfAA9C) was found and characterized. Of all the studies related to AA9, this was the first that maintained the IDR, therefore, we intend to carry out a study comparing AfAA9C and the same truncated enzyme (AfAA9CTR). In this work AfAA9CTR will be obtained by removing the IDR using molecular biology tools to participate in a comparative analysis with AfAA9C that aims to evaluate the influence of the IDR on the biochemical characteristics, as well as on the production/resistance to H2O2 and on the interaction with other oxidative enzymes at CDH