Purification and characterization of an exo-polygalacturonase from the tomato vascular wilt pathogen Fusarium oxysporum f.sp. lycopersici.
An exo-polygalacturonase (EC 3.2.1.15) was purified to apparent homogeneity from cultures of Fusarium oxysporum f.sp. lycopersici on synthetic medium supplemented with citrus pectin, using preparative isoelectric focusing. The enzyme, denominated PG2, had an apparent M(r) of 74000 Da upon SDS-PAGE. The pI of the main PG2 isoform was 4.5, and pH and temperature optima were 5.0 and 55 degrees C, respectively. PG2 hydrolyzed polygalacturonic acid in an exo-manner, as demonstrated by anaysis of degradation products. The enzyme was N-glycosylated. The N-terminal amino acid sequence, L-A-F-N-V-P-S-K-P-P, has no identify to other known polygalacturonases.
Di Pietro
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A
Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, Spain. ge2dipia@uco.es
Roncero
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MI
D004591:Electrophoresis, Polyacrylamide Gel; D005503:Food Additives / Q000378:metabolism; D005670:Fusarium / Q000201:enzymology*; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D007525:Isoelectric Focusing; D018551:Solanum lycopersicum / Q000382:microbiology*; D010368:Pectins / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism
D005503:Food Additives; D010940:Plant Proteins; D010368:Pectins; D006026:Glycoside Hydrolases; C020136:exopolygalacturonase