title: Characterization of neuraminidases produced by various serotypes of Pasteurella haemolytica.
abstract: Neuraminidases produced by 16 strains of Pasteurella haemolytica (serotypes 1 to 16) were characterized by molecular weight, antigenic identity, and substrate specificity. After growth in a chemically defined medium, stage I (lyophilized) culture supernatants were assayed for activity with N-acetylneuramin lactose, human alpha-1-acid glycoprotein, fetuin, colominic acid, and bovine submaxillary mucin. Neuraminidase produced by P. haemolytica serotype A1 (Ph A1) was purified by a combination of salt fractionation, ion-exchange chromatography on DEAE-Sephacel, and gel filtration on Sephadex G-200. Purified Ph A1 neuraminidase was used to immunize rabbits, and the resultant antiserum reduced the activity of Ph A1 neuraminidase by 46%. This antiserum also reduced the activity of neuraminidase produced by the other serotypes by between 15 and 66%. Molecular weight estimates of the neuraminidases produced by the various serotypes were obtained by gel filtration chromatography on Sephadex G-200. Fifteen of the 16 serotypes examined produced a neuraminidase with a molecular weight of approximately 150,000 to 200,000. One serotype (serotype 11) produced no material with neuraminidase activity. In addition, all 15 high-molecular-weight neuraminidases showed similar substrate specificities. That is, they were all most active against N-acetylneuramin lactose and least active against bovine submaxillary mucin. On the basis of these results, it appears that the high-molecular-weight neuraminidases produced by the different P. haemolytica serotypes are quite similar.
authors.affiliation: Department of Microbiology and Immunology, Texas Tech University Health Sciences Center, Lubbock 79430.
authors.forename: D C
authors.initials: DC
authors.lastname: Straus
authors.forename: W L
authors.initials: WL
authors.lastname: Jolley
authors.forename: C W
authors.initials: CW
authors.lastname: Purdy
mesh_terms: D016978:Mannheimia haemolytica / Q000201:enzymology*; D008970:Molecular Weight; D009439:Neuraminidase / Q000276:immunology / Q000378:metabolism*; D009500:Neutralization Tests; D012703:Serotyping; D013379:Substrate Specificity
chemical_list: D009439:Neuraminidase