02108naa a2200253 a 450000100080000000500110000800800410001902200140006010000170007424500820009126000090017352013850018265000250156770000230159270000210161570000220163670000220165870000140168070000190169470000210171370000190173470000250175377300760177819107282011-12-22       2011    bl ---       0--  u    #d  a1570-96391 aMULINARI, F.  aCharacterization of JBURE-IIb isoform of Canavalia ensiformis (L.) DC urease.  c2011  aUreases, 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 (78 kDa) when compared to other plant ureases. Aiming to produce the recombinant protein, we obtained jbure-IIb, with different 3? and 5? ends, encoding a 90 kDa 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.  aCanavalia Ensiformis1 aBECKER-RITT, A. B.1 aDEMARTINI, D. R.1 aLIGABUE-BRAUN, R.1 aSTANISÇUASKI, F.1 aVERLI, H.1 aFRAGOSO, R. R.1 aSCHROEDER, E. K.1 aCARLINI, C. R.1 aGROSSI-de-SÁ, M. F.  tBiochimica et Biophysica Actagv. 1814, n. 12, p. 1758-1768, Dec. 2011.