Mulinari F, Becker-Ritt AB, Demartini DR, Ligabue-Braun R, Stanisçuaski F, Verli H, Fragoso RR, Schroeder EK, Carlini CR, Grossi-de-Sá MF. Characterization of JBURE-IIb isoform of Canavalia ensiformis (L.) DC urease.
BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011;
1814:1758-68. [PMID:
21893219 DOI:
10.1016/j.bbapap.2011.07.022]
[Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 07/20/2011] [Accepted: 07/22/2011] [Indexed: 11/29/2022]
Abstract
Ureases, nickel-dependent enzymes that catalyze the hydrolysis of urea into ammonia and bicarbonate, are widespread in plants, bacteria, and fungi. Previously, we cloned a cDNA encoding a Canavalia ensiformis urease isoform named JBURE-II, corresponding to a putative smaller urease protein (78kDa) when compared to other plant ureases. Aiming to produce the recombinant protein, we obtained jbure-IIb, with different 3' and 5' ends, encoding a 90kDa urease. Three peptides unique to the JBURE-II/-IIb protein were detected by mass spectrometry in seed extracts, indicating that jbure-II/-IIb is a functional gene. Comparative modeling indicates that JBURE-IIb urease has an overall shape almost identical to C. ensiformis major urease JBURE-I with all residues critical for urease activity. The cDNA was cloned into the pET101 vector and the recombinant protein was produced in Escherichia coli. The JBURE-IIb protein, although enzymatically inactive presumably due to the absence of Ni atoms in its active site, impaired the growth of a phytopathogenic fungus and showed entomotoxic properties, inhibiting diuresis of Rhodnius prolixus isolated Malpighian tubules, in concentrations similar to those reported for JBURE-I and canatoxin. The antifungal and entomotoxic properties of the recombinant JBURE-IIb apourease are consistent with a protective role of ureases in plants.
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