title: Neuraminidase production by a Pasteurella haemolytica A1 strain associated with bovine pneumonia.
abstract: The properties of an extracellular neuroaminidase produced by a Pasteurella haemolytica A1 strain (isolated from a case of bovine pneumonia) during growth in a defined medium were examined in this investigation. This enzyme, isolated from concentrated culture supernatants of P. haemolytica A1, was active against N-acetylneuramin lactose, human alpha 1-acid glycoprotein, fetuin, and bovine submaxillary mucin. Neuraminidase production paralleled bacterial growth in a defined medium and was maximal in the stationary phase of growth. The enzyme was purified to homogeneity by a combination of salt fractionation, ion-exchange chromatography on DEAE-Sephacel, and gel filtration on Sephadex G-200. These procedures yielded an enzyme preparation that possessed a specific activity of 100.62 mumol of sialic acid released per min per mg of protein against human alpha 1-acid glycoprotein. The Km value for this enzyme with human alpha 1-acid glycoprotein as the substrate was 1.1 mg/ml, and the enzyme possessed a pH optimum of 6.5. The P. haemolytica A1 neuraminidase had a molecular weight of approximately 150,000 as estimated by gel filtration and approximately 170,000 when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme was stable at 4 degrees C for 3 h. At 37 degrees C for 3 h, 25% of enzymatic activity was lost. Approximately 55% of the enzyme activity was lost within 30 min at 50 degrees C, with greater than 70% of the enzyme activity being destroyed within 10 min at temperatures of > or = 65 degrees C.
authors.affiliation: Department of Microbiology, Texas Tech University Health Sciences Center, Lubbock 79430.
authors.forename: D C
authors.initials: DC
authors.lastname: Straus
authors.forename: P J
authors.initials: PJ
authors.lastname: Unbehagen
authors.forename: C W
authors.initials: CW
authors.lastname: Purdy
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology*; D002455:Cell Division; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000378:metabolism; D006358:Hot Temperature / Q000009:adverse effects; D006863:Hydrogen-Ion Concentration; D016978:Mannheimia haemolytica / Q000201:enzymology* / Q000502:physiology; D008970:Molecular Weight; D009439:Neuraminidase / Q000096:biosynthesis* / Q000302:isolation & purification; D011014:Pneumonia / Q000382:microbiology / Q000662:veterinary*; D013379:Substrate Specificity
chemical_list: D006023:Glycoproteins; D009439:Neuraminidase