Common amino acid domain among endopolygalacturonases of ascomycete fungi

• Published in: Applied and Environmental Microbiology Vol. 56; no. 8; pp. 2522 - 2528
• Main Authors: Keon, J.P.R. (University of Bristol, Bristol, United Kingdom), Waksman, G
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.08.1990
• Subjects: ACIDE AMINE; ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Amino Acid Sequence; Amino Acids - analysis; AMINOACIDOS; Ascomycota - enzymology; ASPERGILLUS; Aspergillus niger; Aspergillus niger - enzymology; Biological and medical sciences; COLLETOTRICHUM; Colletotrichum lindemuthianum; EPURATION; Fundamental and applied biological sciences. Psychology; Glycoside Hydrolases - isolation & purification; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; HIDROLASAS; Hydrogen-Ion Concentration; HYDROLASE; Immunochemistry; isoelectric focusing; Kinetics; Microbiology; Molecular Sequence Data; Molecular Weight; Mycology; PESO MOLECULAR; POIDS MOLECULAIRE; Polygalacturonase - immunology; Polygalacturonase - isolation & purification; Polygalacturonase - metabolism; PURIFICACION; SCLEROTINIA; Sclerotinia sclerotiorum; Sequence Homology, Nucleic Acid; Species Specificity; Temperature; Characterization; Fungi; Purification; N terminal-Sequence; Immunoblotting assay; Homology; Isoforming; Ascomycetes; Polygalacturonase; Comparative study; Aminoacid sequence; Thallophyta
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.56.8.2522-2528.1990

The endopolygalacturonase (EC 3.2.1.15) enzymes produced in vitro by three ascomycete fungi, Aspergillus niger, Sclerotinia sclerotiorum, and Collelotrichum lindemuthianum were studied by using thin-layer isoelectric focusing and activity stain overlay techniques. The polygalacturonases from A. niger and S. sclerotiorum consisted of numerous isoforms, whereas the endopolygalacturonase from C. lindemuthianum consisted of a single protein species. The most abundant endopolygalacturonase isoform produced by each of these organisms was purified and characterized. Biochemical parameters, including molecular weight, isoelectric point, kinetic parameters, temperature and pH optima, and thermal stability, were determined. Considerable differences in physical and chemical properties were demonstrated among these fungal polygalacturonases. Antibodies raised against individual proteins exhibited little cross-reaction, suggesting that these enzymes differ structurally as well as biochemically. In contrast, the analysis of the N-terminal amino acid sequences of the three proteins showed extensive homology, particularly in a region labeled domain 1 in which 84% of the amino acids were conserved