title: Mode of action and antifungal properties of two cold-adapted chitinases.
abstract: The mode of action of two chitinases from the Antarctic Arthrobacter sp. strain TAD20 on N-acetyl-chitooligomers and chitin polymers has been elucidated. Identification of the length of chitin oligomers following enzymatic hydrolysis was verified by using HPLC-based analysis. It was observed that the length of the oligomer is important for enzyme action. The enzymes cannot effectively hydrolyze chitin oligomers with a degree of polymerization lower than four. ArChiA is an endochitinase which hydrolyzes chitin substrates randomly, whereas ArChiB is an exochitinase which degrades chitin chains and N-acetyl-chitooligomers from the nonreducing end, releasing N- N'-diacetyl-chitobiose. ArChiB (100 microg/ml) inhibited spore germination and hyphal elongation of the phytopathogenic fungus Botrytis cinerea by 15% and 30%, respectively. A more pronounced effect was observed with ArChiA (100 microg/ml) resulting in 70% inhibition of spore germination and 60% inhibition of germ tube elongation. A slight additive effect was observed, when the two enzymes were used in combination, only on the inhibition of germ tube elongation.
authors.affiliation: Department of Biology, Division of Applied Biology and Biotechnology, University of Crete, PO Box 1470, 71110 Heraklion, Crete, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Mavromatis
authors.forename: Matteo
authors.initials: M
authors.lastname: Lorito
authors.forename: Sheridan L
authors.initials: SL
authors.lastname: Woo
authors.forename: Vassilis
authors.initials: V
authors.lastname: Bouriotis
mesh_terms: D000935:Antifungal Agents / Q000378:metabolism / Q000494:pharmacology*; D020171:Botrytis / Q000187:drug effects* / Q000502:physiology; D002686:Chitin / Q000378:metabolism; D002688:Chitinases / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D003080:Cold Temperature; D009844:Oligosaccharides / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D009844:Oligosaccharides; D002686:Chitin; D002688:Chitinases