Identification, cloning, and characterization of a novel chitinase from leaf-cutting ant Atta sexdens: An enzyme with antifungal and insecticidal activity

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Micocci, Kelli C. ; Moreira, Ariele C. ; Sanchez, Amanda D. ; Pettinatti, Jessica L. ; Rocha, Marina C. ; Dionizio, Bruna S. ; Correa, Katia C. S. ; Malavazi, Iran ; Wouters, Felipe C. ; Bueno, Odair C. ; Souza, Dulce Helena F.

• Document type: Journal article
• Source: BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS; v. 1867, n. 1, p. 10-pg., 2023-01-01.

Abstract

Chitinases are enzymes that degrade chitin, a polysaccharide found in the exoskeleton of insects, fungi, yeast, and internal structures of other vertebrates. Although chitinases isolated from bacteria, fungi and plants have been reported to have antifungal or insecticide activities, chitinases from insects with these activities have been sel-domly reported. In this study, a leaf-cutting ant Atta sexdens DNA fragment containing 1623 base pairs was amplified and cloned into a vector to express the protein (AsChtII-C4B1) in Pichia pastoris. AsChtII-C4B1, which contains one catalytic domain and one carbohydrate-binding module (CBM), was secreted to the extracellular medium and purified by ammonium sulfate precipitation followed by nickel column chromatography. AsChtII-C4B1 showed maximum activity at pH 5.0 and 55 degrees C when tested against colloidal chitin substrate and main-tained >60% of its maximal activity in different temperatures during 48 h. AsChtII-C4B1 decreased the survival of Spodoptera frugiperda larvae fed with an artificial diet that contained AsChtII-C4B1. Our results have indicated that AsChtII-C4B1 has a higher effect on larva-pupa than larva-larva molts. AsChtII-C4B1 activity targets more specifically the growth of filamentous fungus than yeast. This work describes, for the first time, the obtaining a recombinant chitinase from ants and the characterization of its insecticidal and antifungal activities. (AU)

• FAPESP's process: 12/25299-6 - Integrated studies for leaf cutting control
• Grantee: João Batista Fernandes
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/06198-8 - Functional study of acetylcholinesterase (AChE) and other enzymes of Atta Sexdens rubropilosa and their symbiotic fungus Leucoagaricus gongylophorus, their immobilization in electrode and search of specific inhibitors
• Grantee: Kelli Cristina Micocci
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/19694-3 - The role of heat shock proteins HsfA and Hsp90 and the regulator SmiA at cell wall integrity pathway activity in the opportunistic human pathogen Aspergillus fumigatus
• Grantee: Iran Malavazi
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/06297-9 - Production and characterization of chimeric proteins containing chitinase catalytic domain and modules for chitin binding
• Grantee: Dulce Helena Ferreira de Souza
• Support Opportunities: Regular Research Grants