title: Fractionation and characterization of surface antigens from group A Neisseria meningitidis.
abstract: Group A meningococcal surface components were first subjected to fractionation with a mixture of chloroform-methanol. Sodium dodecyl sulfate-acrylamide gel electrophoresis of the aqueous phase containing 30 to 40% of the original material revealed only two polypeptide components and a slowly migrating carbohydrate component. The soluble fraction of the interphase was found to contain most of the bacterial surface proteins and the chloroform-methanol phase essentially all of the lipid components. The components of the aqueous phase were further fractionated by use of the hydrophobic affinity column, 4-phenylbutylamino-Sepharose and gradient elution with NaCl to yield fractions I and II. Fraction II was further separated into a minor and a major component (IIb) with Sepharose G-200. Fraction I contained the group A polysaccharide in ionic linkages with a minor polypeptide component (6%). It elicited bactericidal antibodies in rabbits and protected mice against homologous challenge, whereas the polysaccharide alone was non-immunogenic in these animals. Fraction IIb was a polysaccharide-polypeptide complex with unknown linkages; it induced a low concentration of rabbit antibodies that were bactericidal to group A and C meningococci. Mice vaccinated with fraction IIb were most resistant to homologous challenge and the resistance was also extended to challenges with group B and C cells. Fractions I and IIb appeared to be useful alternatives to the currently employed group-specific polysaccharide vaccines for the protection against drug-resistant meningococci. A simplified procedure for the preparation of group-specific polysaccharide was presented.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000942:Antigens, Bacterial / Q000302:isolation & purification*; D001431:Bacteriological Techniques; D001770:Blood Bactericidal Activity; D002082:Butylamines; D002241:Carbohydrates / Q000032:analysis; D005591:Chemical Fractionation / Q000379:methods; D003488:Cyanogen Bromide; D004247:DNA / Q000032:analysis; D004126:Dimethylformamide; D004589:Electrophoresis, Disc; D007106:Immune Sera; D007114:Immunization; D007117:Immunization, Secondary; D007156:Immunologic Memory; D051379:Mice; D008815:Mice, Inbred Strains; D009345:Neisseria meningitidis / Q000276:immunology*; D009584:Nitrogen / Q000032:analysis; D011233:Precipitin Tests; D012313:RNA / Q000032:analysis; D011817:Rabbits / Q000276:immunology; D012685:Sepharose / Q000031:analogs & derivatives; D012882:Skin Tests; D013053:Spectrophotometry
chemical_list: D000596:Amino Acids; D000942:Antigens, Bacterial; D002082:Butylamines; D002241:Carbohydrates; D007106:Immune Sera; D012313:RNA; D004126:Dimethylformamide; D004247:DNA; D012685:Sepharose; D009584:Nitrogen; D003488:Cyanogen Bromide