title: Purification and characterization of an antifungal chitinase in jelly fig (Ficus awkeotsang) achenes.
abstract: 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 K(m), k(cat), optimal pH and temperature of this putative chitinase were determined to be 0.076 mM, 0.089 s(-1), pH 4, and 60 degrees C, respectively. The purified 30-kDa protein was thermostable (retaining activity up to 65 degrees C for several hours) and could be stored at 4 degrees 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.
authors.affiliation: Graduate Institute of Biotechnology, National Chung-Hsing University, Taichung, Taiwan 40227, ROC.
authors.forename: Yu-Ching
authors.initials: YC
authors.lastname: Li
authors.forename: Chen-Tien
authors.initials: CT
authors.lastname: Chang
authors.forename: Eric S L
authors.initials: ES
authors.lastname: Hsiao
authors.forename: Joyce S F
authors.initials: JS
authors.lastname: Hsu
authors.forename: Jenn-Wen
authors.initials: JW
authors.lastname: Huang
authors.forename: Jason T C
authors.initials: JT
authors.lastname: Tzen
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification*; D015153:Blotting, Western; D002688:Chitinases / Q000737:chemistry / Q000302:isolation & purification*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D030681:Ficus / Q000201:enzymology*
chemical_list: D000935:Antifungal Agents; D002688:Chitinases