Characterization of a grape class IV chitinase.
A chitinase was purified from Vitis vinifera Manzoni Bianco grape juice and characterized. On the basis of proteomic analysis of tryptic peptides, a significant match identified the enzyme as a type IV grape chitinase previously found in juices of other V. vinifera varieties. The optimal pH and temperature for activity toward colloidal chitin were found to be 6 and 30 °C, respectively. The enzyme was found to hydrolyze chitin and oligomers of N-acetylglucosamine, generating N,N'-diacetylchitobiose and N-acetylglucosamine as products, but was inactive toward N,N'-diacetylchitobiose. The enzyme exhibited both endo- and exochitinase activities. Because yeast contains a small amount of chitin in the cell wall, the possibility of growth inhibition was tested. At a concentration and pH expected in ripe grapes, no inhibition of wine yeast growth by the chitinase was observed.
Department of Agronomy, Food, Natural Resources, Animals and the Environment, Padova University , 35020 Legnaro, Italy.
Simone
S
Vincenzi
Jan
J
Bierma
Samanthi I
SI
Wickramasekara
Andrea
A
Curioni
Diana
D
Gazzola
Alan T
AT
Bakalinsky
D000117:Acetylglucosamine / Q000737:chemistry; D001628:Beverages / Q000032:analysis; D002473:Cell Wall / Q000737:chemistry; D002686:Chitin / Q000737:chemistry; D002688:Chitinases / Q000737:chemistry*; D002853:Chromatography, Liquid; D004187:Disaccharides / Q000737:chemistry; D005638:Fruit / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010940:Plant Proteins / Q000737:chemistry*; D040901:Proteomics; D012441:Saccharomyces cerevisiae / Q000254:growth & development; D013379:Substrate Specificity; D053719:Tandem Mass Spectrometry; D013696:Temperature; D027843:Vitis / Q000201:enzymology*
D004187:Disaccharides; D010940:Plant Proteins; D002686:Chitin; C010913:N,N-diacetylchitobiose; D002688:Chitinases; D000117:Acetylglucosamine