title: Purification and some properties of a protease from Streptomyces limosus.
abstract: Streptomyces limosus was selected because it secreted a novel protease that catalyzed the synthetic reaction forming Pro-Pro-Pro from Pro-Pro. The protease was purified to an electrophoretically homogeneous state and an activity of more than about 20,000-fold that of the culture broth. The molecular mass of the enzyme was estimated to be 50 kDa by SDS-polyacrylamide gel electrophoresis. The enzyme was most active in alkaline pH for the synthetic reaction producing Pro-Pro-Pro from Pro-Pro, although for the hydrolytic reaction forming proline it was most active in neutral pH. The enzyme was inhibited by 1,2-epoxy-3-(p-nitrophenoxy)propane (EPNP) and diazoacetyl-DL-norleucine methyl ester (DAN). It can be considered that this enzyme belongs to the class of aspartic proteases. The substrate specificity indicates that this enzyme has a strong affinity for proline as a N-terminal amino acid of peptides.
authors.affiliation: Osaka Municipal Technical Research Institute, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Muro
authors.forename: Y
authors.initials: Y
authors.lastname: Watanabe
authors.forename: A
authors.initials: A
authors.lastname: Sugihara
authors.forename: Y
authors.initials: Y
authors.lastname: Shimada
authors.forename: T
authors.initials: T
authors.lastname: Nagao
authors.forename: S
authors.initials: S
authors.lastname: Takenishi
authors.forename: Y
authors.initials: Y
authors.lastname: Tominaga
mesh_terms: D000595:Amino Acid Sequence; D000645:Ammonium Sulfate; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D004151:Dipeptides / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011492:Protein Hydrolysates / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013302:Streptomyces / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D004151:Dipeptides; D011492:Protein Hydrolysates; D010450:Endopeptidases; D000645:Ammonium Sulfate