Crystal structure analysis of peroxidase from the palm tree Chamaerops excelsa

Author(s)

Bernardes, Amanda ^[1] ; Textor, Larissa C. ^[1] ; Santos, Jademilson C. ^[1] ; Cuadrado, Nazaret Hidalgo ^[2] ; Kostetsky, Eduard Ya. ^[3] ; Roig, Manuel G. ^[2] ; Bavro, Vassiliy N. ^[4] ; Muniz, Joao R. C. ^[1] ; Shnyrov, Valery L. ^[5] ; Polikarpov, Igor ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Salamanca, Fac Quim, Dept Quim Fis, E-37008 Salamanca - Spain

^[3] Far Eastern State Univ, Dept Biochem Microbiol & Biotechnol, Vladivostok 690600 - Russia

^[4] Univ Birmingham, Inst Microbiol & Infect, Birmingham B15 2TT, W Midlands - England

^[5] Univ Salamanca, Fac Biol, Dept Bioquim & Biol Mol, Salamanca 37007 - Spain

• Document type: Journal article
• Source: Biochimie; v. 111, p. 58-69, APR 2015.
• Web of Science Citations: 8

Abstract

Palm tree peroxidases are known to be very stable enzymes and the peroxidase from the Chamaerops excelsa (CEP), which has a high pH and thermal stability, is no exception. To date, the structural and molecular events underscoring such biochemical behavior have not been explored in depth. In order to identify the structural characteristics accounting for the high stability of palm tree peroxidases, we solved and refined the X-ray structure of native CEP at a resolution of 2.6 angstrom. The CEP structure has an overall fold typical of plant peroxidases and confirmed the conservation of characteristic structural elements such as the heme group and calcium ions. At the same time the structure revealed important modifications in the amino acid residues in the vicinity of the exposed heme edge region, involved in substrate binding, that could account for the morphological variations among palm tree peroxidases through the disruption of molecular interactions at the second binding site. These modifications could alleviate the inhibition of enzymatic activity caused by molecular interactions at the latter binding site. Comparing the CEP crystallographic model described here with other publicly available peroxidase structures allowed the identification of a noncovalent homodimer assembly held together by a number of ionic and hydrophobic interactions. We demonstrate, that this dimeric arrangement results in a more stable protein quaternary structure through stabilization of the regions that are highly dynamic in other peroxidases. In addition, we resolved five N-glycosylation sites, which might also contribute to enzyme stability and resistance against proteolytic cleavage. (C) 2015 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved. (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 type: Program for Research on Bioenergy (BIOEN) - Thematic Grants
• FAPESP's process: 10/52362-5 - Targeted analysis of microbial lignocellulolytic secretomes: a new approach to enzyme discovery
• Grantee: Igor Polikarpov
• Support type: Regular Research Grants
• FAPESP's process: 09/05349-6 - Expression and purification of cellobiohydrolase I from the filamentous fungus Trichoderma harzianum
• Grantee: Bruno Luan Soares Paula de Mello
• Support type: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 12/22802-9 - Functional and Structural Studies of Carbohydrate Binding Modules of Glycosil Hydrolases
• Grantee: Amanda Bernardes Muniz
• Support type: Scholarships in Brazil - Post-Doctorate