Identification and partial characterization of a chitinase and a β-1,3-glucanase from Copernicia cerifera wax

The presence of proteins in plant cuticular waxes has been known for a long time. The aim of the present work is to investigate the presence of defense-related proteins in the wax of the "Carnauba" (Copernicia cerifera) tree, an economically important tree of the palm family in the northeastern region of Brazil. Results from our laboratory have shown the presence of protein in different fractions isolated from this wax. A DEAE-Sepharose anion exchange column was employed for further discrimination of proteins from different fractions. The samples were visualized by SDS-Tricine-gel electrophoresis. The acidic and basic fractions were recovered by freeze-drying and fractions with antifungic activity identified by assaying for inhibition of fungi growth. beta-1,3-glucanase and chitinase activities. Our results showed the presence of enzymatic activities in different wax fractions. Isolated proteins were submitted to automated N-terminal amino acid sequencing and obtained sequences showed the presence of proteins with a high degree of homology to class III chitinases and to beta-1,3 glucanase. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.