title: A novel N(alpha)-acetyl alanine aminopeptidase from Allomyces arbuscula.
abstract: An N(alpha)-acetyl alanine aminopeptidase has been purified from the aquatic fungus Allomyces arbuscula. The apparent molecular mass of the enzyme was estimated to be 280 kDa by gel filtration through calibrated Sephacryl S300 column. In SDS-PAGE, the purified enzyme appeared as a single band of M(r) 80 kDa. Catalytic activity of the enzyme was inhibited by specific serine protease inhibitors, 3,4-DCI and APMSF, as well as SH reacting compounds, HgCl(2) and iodoacetate, indicating that the enzyme is a serine protease with some functional SH group(s) involved in the catalytic reaction. 3H-DFP was used to label the reactive serine of the enzyme. When the labeled protein was analyzed in SDS-PAGE, most of the label appeared in the M(r) 80 kDa band, however, a few additional faster migrating minor bands were also seen, probably representing a minor degradation product of the enzyme. The enzyme cleaved mainly N(alpha)-acetlylated alanine, although a small but negligible activity was also obtained with acetylated leucine and phenylalanine. The role of the enzyme in N-end rule proteolysis is discussed.
authors.affiliation: Laboratoire de Bioénergétique et de Microbiologie, Université de Genève, 3, place de l'Université, 1211 4, Genève, Switzerland.
authors.forename: Raniera
authors.initials: R
authors.lastname: Beti
authors.forename: Arlette
authors.initials: A
authors.lastname: Cattaneo
authors.forename: Jean Marc
authors.initials: JM
authors.lastname: Gabriel
authors.forename: Mukti
authors.initials: M
authors.lastname: Ojha
mesh_terms: D000107:Acetylation; D001665:Binding Sites; D018826:CD13 Antigens / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D002850:Chromatography, Gel; D008411:Chytridiomycota / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007531:Isoflurophate / Q000737:chemistry / Q000494:pharmacology; D007700:Kinetics; D008970:Molecular Weight; D012694:Serine / Q000737:chemistry / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D013347:Subcellular Fractions / Q000737:chemistry / Q000187:drug effects / Q000201:enzymology; D013379:Substrate Specificity; D013696:Temperature; D015032:Zinc / Q000494:pharmacology
chemical_list: D002614:Chelating Agents; D015842:Serine Proteinase Inhibitors; D007531:Isoflurophate; D012694:Serine; D018826:CD13 Antigens; D015032:Zinc