title: Production, purification and characterization of a 50-kDa extracellular metalloprotease from Serratia marcescens.
abstract: The extracellular metalloprotease (SMP 6.1) produced by a soil isolate of Serratia marcescens NRRL B-23112 was purified and characterized. SMP 6.1 was purified from the culture supernatant by ammonium sulfate precipitation, acetone fractional precipitation, and preparative isoelectric focusing. SMP 6.1 has a molecular mass of approximately 50,900 Da by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE). The following substrates were hydrolyzed: casein, bovine serum albumin, and hide powder. SMP 6.1 has the characteristics of a metalloprotease, a pH optimum of 10.0, and a temperature optimum of 42 degrees C. The isoelectric point of the protease is 6.1. Restoration of proteolytic activity by in-gel renaturation after SDS-PAGE indicates a single polypeptide chain. SMP 6.1 is inhibited by EDTA (9 micrograms/ml) and not inhibited by antipain dihydrochloride (120 micrograms/ml), aprotinin (4 micrograms/ml), bestatin (80 micrograms/ml), chymostatin (50 micrograms/ml), E-64 (20 micrograms/ml), leupeptin (4 micrograms/ml), Pefabloc SC (2000 micrograms/ml), pepstatin (4 micrograms/ml), phosphoramidon (660 micrograms/ml), or phenylmethylsulfonyl fluoride (400 micrograms/ml). SMP 6.1 retains full activity in the presence of SDS (1% w/v), Tween-20 (1% w/v), Triton X-100 (1% w/v), ethanol (5% v/v), and 2-mercaptoethanol (0.5% v/v). The extracellular metalloprotease SMP 6.1 differs from the serratiopeptidase (Sigma) produced by S. marcescens ATCC 27117 in the following characteristics: isoelectric point, peptide mapping and nematolytic properties.
authors.affiliation: Department of Molecular Biology and Microbiology, University of Central Florida, Orlando 32816-2360, USA. petes@wsunix.wsu.edu
authors.forename: P R
authors.initials: PR
authors.lastname: Salamone
authors.forename: R J
authors.initials: RJ
authors.lastname: Wodzinski
mesh_terms: D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008666:Metalloendopeptidases / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D010449:Peptide Mapping; D012706:Serratia marcescens / Q000201:enzymology*; D013696:Temperature
chemical_list: D008666:Metalloendopeptidases