Purification and characterization of two endopolygalacturonases from Sclerotinia sclerotiorum

• Published in: Biochimica et biophysica acta Vol. 1073; no. 1; pp. 43 - 48
• Main Authors: Waksman, G, Keon, J.P.R, Turner, G
• Format: Journal Article
• Language: English
• Published: Netherlands 23.01.1991
• Subjects: amino acid composition; Amino Acid Sequence; amino acids; Amino Acids - analysis; Ascomycota - enzymology; Blotting, Western; Cross Reactions; enzyme activity; Glycosylation; Hydrogen-Ion Concentration; Isoelectric Point; isozymes; Molecular Sequence Data; Molecular Weight; polygalacturonase; Polygalacturonase - chemistry; Polygalacturonase - immunology; Polygalacturonase - isolation & purification; Polygalacturonase - metabolism; purification; Sclerotinia sclerotiorum; Temperature
• ISSN: 0006-3002; 1878-2434

The endopolygalacturonase (EC 3.2.1.15) enzymes produced in vitro by Sclerotinia sclerotiorum were found to consist of numerous isoforms covering a broad pI range. Two of the isoforms, labelled PG2 and PG3, were purified using gel-filtration chromatography, isoelectric focusing and anion-exchange chromatography. The pIs of PG2 and PG3 were, respectively, 4.8 and 4.9. Their molecular weights were similar. Both enzymes hydrolysed 0.9% of the bonds in reaching a 50% reduction in viscosity. However, their enzymic parameters were different. Their amino acid compositions differed only in the aspartic acid-asparagine content. The N-terminal sequences differed at the fourth amino acid only. PG2 and PG3 exhibited a high level of glycosylation compared to a similar enzyme isolated from Aspergillus niger. Antibody raised against PG3 was shown to crossreact with PG2, but not with the enzyme purified from Aspergillus niger.