Purification and Characterization of an Antifungal Chitinase in Jelly Fig (Ficus awkeotsang) Achenes.

Yu-Ching Li; Chen-Tien Chang; Eric S. L. Hsiao; Joyce S. F. Hsu; Jenn-Wen Huang; Jason T. C. Tzen

A method was developed to purify a 30-kDa protein from jelly fig (Ficus awkeotsang) pericarp, including preparation of jelly curd from achenes, extraction of proteins from the curd, and isolation of the 30-kDa protein by anion-exchanger and gel filtration. Chitinase activity was detected in the purified 30-kDa protein by activity staining in both non-denaturing gel electrophoresis and SDS-PAGE. Isoelectrofocusing showed that the isoelectric point of the 30-kDa protein was lower than pH 3.5. The Km, kcat, optimal pH and temperature of this putative chitinase were determined to be 0.076 mM, 0.089 s-1, pH 4, and 60°C, respectively. The purified 30-kDa protein was thermostable (retaining activity up to 65°C for several hours) and could be stored at 4°C for a year without apparent loss of chitinase activity. Antifungal activity of this putative chitinase was measured in terms of inhibition of Colletotrichum gloeosporioides spore germination.

FICUS (Plants); CHITINASE; PLANT spores; COLLETOTRICHUM

Plant & Cell Physiology, 2003, Vol 44, Issue 11, p1162

0032-0781

Academic Journal

10.1093/pcp/pcg141