title: Purification and characterization of polygalacturonases produced by the hyphal fungus Aspergillus niger.
abstract: Five endo-polygalacturonases (poly(1,4-alpha-D-galacturonide) glycanohydrolase, EC 3.2.1.15) and one exo-polygalacturonase (poly(1,4-alpha-D-galacturonide) galacturonohydrolase, EC 3.2.1.67) were isolated from a commercial pectinase preparation derived from Aspergillus niger. All five endo-enzymes could be purified to homogeneity by affinity chromatography on cross-linked alginate, ion-exchange chromatography, chromatofocusing, and gel permeation chromatography. The exo-polygalacturonase was only partially purified but free from endo-polygalacturonase activity. The two most abundant endo-polygalacturonases (endo-I and endo-II), with molecular masses of 55 and 38 kDa, respectively, are quite different with respect to their isoelectric point, specific activity, mode of action on oligomeric substrates, and amino acid composition. The physicochemical properties of the other three endo-polygalacturonases (endo-IIIA, endo-IIIB, and endo-IV), present in low amounts, are quite similar to those of the endo-I type. The pH optima of all these endo-polygalacturonases are in the range of 4.3-4.9.
authors.affiliation: Department of Genetics, Agricultural University, Wageningen, The Netherlands.
authors.forename: H C
authors.initials: HC
authors.lastname: Kester
authors.forename: J
authors.initials: J
authors.lastname: Visser
mesh_terms: D000464:Alginates; D000596:Amino Acids / Q000032:analysis; D001234:Aspergillus niger / Q000201:enzymology*; D015153:Blotting, Western; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002845:Chromatography; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D004811:Epichlorohydrin; D020723:Glucuronic Acid; D006026:Glycoside Hydrolases / Q000302:isolation & purification*; D006603:Hexuronic Acids; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007526:Isoelectric Point; D046911:Macromolecular Substances; D008970:Molecular Weight; D010368:Pectins / Q000378:metabolism; D011096:Polygalacturonase / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D000464:Alginates; D000596:Amino Acids; D003432:Cross-Linking Reagents; D006603:Hexuronic Acids; D046911:Macromolecular Substances; D004811:Epichlorohydrin; D010368:Pectins; D020723:Glucuronic Acid; D006026:Glycoside Hydrolases; D011096:Polygalacturonase; C003181:polygalacturonic acid