title: Purification, characterization, and antifungal activity of chitinases from pineapple (Ananas comosus) leaf.
abstract: Three chitinases, designated pineapple leaf chitinase (PL Chi)-A, -B, and -C were purified from the leaves of pineapple (Ananas comosus) using chitin affinity column chromatography followed by several column chromatographies. PL Chi-A is a class III chitinase having a molecular mass of 25 kDa and an isoelectric point of 4.4. PL Chi-B and -C are class I chitinases having molecular masses of 33 kDa and 39 kDa and isoelectric points of 7.9 and 4.6 respectively. PL Chi-C is a glycoprotein and the others are simple proteins. The optimum pHs of PL Chi-A, -B, and -C toward glycolchitin are pH 3, 4, and 9 respectively. The chitin-binding ability of PL Chi-C is higher than that of PL Chi-B, and PL Chi-A has lower chitin-binding ability than the others. At low ionic strength, PL Chi-B exhibits strong antifungal activity toward Trichoderma viride but the others do not. At high ionic strength, PL Chi-B and -C exhibit strong and weak antifungal activity respectively. PL Chi-A does not have antifungal activity.
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Agriculture, Ryukyu University, Okinawa, Japan. tokey@agr.u-ryukyu.ac.jp
authors.forename: Toki
authors.initials: T
authors.lastname: Taira
authors.forename: Noriko
authors.initials: N
authors.lastname: Toma
authors.forename: Masanobu
authors.initials: M
authors.lastname: Ishihara
mesh_terms: D000595:Amino Acid Sequence; D031230:Ananas / Q000201:enzymology*; D000935:Antifungal Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D050260:Carbohydrate Metabolism; D002688:Chitinases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D013696:Temperature; D014242:Trichoderma / Q000187:drug effects
chemical_list: D000935:Antifungal Agents; D002688:Chitinases