Functional and structural characterization of a novel GH3 β-glucosidase from the gut metagenome of the Brazilian Cerrado termite Syntermes wheeleri

Raul Alcântara Teixeira Lima, Gideane De Oliveira, Amanda Araújo Souza, Fabyano Alvares Cardoso Lopes, Renata Henrique Santana, Paula Istvan, Betania Ferraz Quirino, João Barbosa, Sonia De Freitas, Aisel Valle Garay, Ricardo Henrique Krüger

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

In this study, a GH3 family β-glucosidase (Bgl7226) from metagenomic sequences of the Syntermes wheeleri gut, a Brazilian Cerrado termite, was expressed, purified and characterized. The enzyme showed two optimum pHs (pH 7 and pH 10), and a maximum optimum temperature of about 40 °C using 4-Nitrophenyl β-D-glucopyranoside (pNPG) as substrate. Bgl7226 showed higher enzymatic activity at basic pH, but higher affinity (Km) at neutral pH. However, at neutral pH the Bgl7226 enzyme showed higher catalytic efficiency (kcat/Km) for pNPG substrate. Predictive analysis about the enzyme structure-function relationship by sequence alignment suggested the presence of multi-domains and conserved catalytic sites. Circular dichroism results showed that the secondary structure composition of the enzyme is pH-dependent. Small conformational changes occurred close to the optimum temperature of 40 o C, and seem important for the highest activity of Bgl7226 observed at pH 7 and 10. In addition, the small transition in the unfolding curves close to 40 o C is typical of intermediates associated with proteins structured in several domains. Bgl7226 has significant β-glucosidase activity which could be attractive for biotechnological applications, such as plant roots detoxification; specifically, our group is interested in cassava roots (Manihot esculenta) detoxification.

Original languageEnglish
Pages (from-to)822-834
Number of pages13
JournalInternational Journal of Biological Macromolecules
Volume165
DOIs
StatePublished - 15 Dec 2020

Keywords

  • GH3-β-glucosidase
  • Metagenome
  • Syntermes wheeleri

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • Molecular Biology

Fingerprint

Dive into the research topics of 'Functional and structural characterization of a novel GH3 β-glucosidase from the gut metagenome of the Brazilian Cerrado termite Syntermes wheeleri'. Together they form a unique fingerprint.

Cite this