Crystal structure analysis of peroxidase from the palm tree Chamaerops excelsa

Research output: Contribution to journalArticle

Authors

  • Amanda Bernardes
  • Larissa C Textor
  • Jademilson C Santos
  • Nazaret Hidalgo Cuadrado
  • Eduard Ya Kostetsky
  • Manuel G Roig
  • João R C Muniz
  • Valery L Shnyrov
  • Igor Polikarpov

Colleges, School and Institutes

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 Å. 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.

Bibliographic note

Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Details

Original languageEnglish
Pages (from-to)58-69
Number of pages12
JournalBiochimie
Volume111
Early online date7 Feb 2015
Publication statusPublished - 1 Apr 2015