Anomalous electrophoretic behavior of a chitinase isoform from grape berries and wine in glycol chitin-containing sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels.
An anomalous electrophoretic behavior of a chitinase isoform present in both grape (Vitis vinifera L.) berries and wine was observed in glycol chitin-containing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels. A progressive shift of the relative molecular mass M(r) of the enzyme (from approximately 30,500 up to approximately 57,700) with increasing glycol chitin concentration in the gels up to 0.1% was revealed when samples were electrophoresed under nonreducing conditions, whereas the presence of glycol chitin had no effects when samples were reduced before SDS-PAGE separation. The M(r) of other grape and wine chitinase isoforms as well as that of the chitinase from pomegranate (Punica granatum L.) fruit was unaffected by the presence of the substrate in the gel under both reducing and nonreducing conditions. Since the enzymes were inactive during the electrophoretic separation, it is likely that the retarding effect of glycol chitin observed specifically for the unreduced chitinase band from grape and wine was due to an interaction between the substrate and a chitin-binding domain different from the catalytic site, such as that typical of class I and class IV chitinases.
Vincenzi
Simone
S
Dipartimento di Biotecnologie agrarie, Facoltà di Agraria, Università di Padova, Padova, Italy.
Curioni
Andrea
A
D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry*; D002688:Chitinases / Q000737:chemistry / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D007527:Isoenzymes / Q000737:chemistry / Q000302:isolation & purification; D008970:Molecular Weight; D027843:Vitis / Q000201:enzymology*; D014920:Wine
D007527:Isoenzymes; D002686:Chitin; C031610:glycolchitin; D002688:Chitinases