title: Protective and other biological properties of Bacillus anthracis soluble antigens.
abstract: The soluble antigens were explored of the culture filtrate (CF) derived during static growth of B. anthracis vaccine strain 34F2 on a medium containing casein hydrolysate. Electrofocusing of CF preparations revealed that the protective activity was distributed over a wide range of pH 3-7. The most pronounced and stable protective activity was observed at pH 4.6-4.8. Following toxin factors were isolated and identified: protective antigen (87 kD), oedema factor (87 kD) and lethal factor (78-81 kD). The greatest protective activity was associated with antigens characterized by a molecular weight of 78-87 kD and toxic activity. Preparations of the oedema and lethal factors had the same protective activity as protective antigen (PA) preparations. Other CF soluble antigens protected about 30% of immunized guinea pigs. A protein was isolated with a molecular weight of 80 kD and isoelectric point at pH 5.3-5.7 which was not toxic and did not form toxic mixtures in association with other toxin factors; this protein featured a high immunogenic activity, however, it protected only 31% of immunized animals. Factors are analyzed which determine differences in the protective effects of live and chemical vaccines.
authors.affiliation: Central Research Institute for Epidemiology of the USSR, Ministry of Health, Moscow.
authors.forename: V A
authors.initials: VA
authors.lastname: Abalakin
authors.forename: T D
authors.initials: TD
authors.lastname: Cherkasova
authors.forename: L V
authors.initials: LV
authors.lastname: Sergeeva
authors.forename: B L
authors.initials: BL
authors.lastname: Cherkassky
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000942:Antigens, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D001408:Bacillus anthracis / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D006168:Guinea Pigs; D006863:Hydrogen-Ion Concentration; D005779:Immunodiffusion; D007525:Isoelectric Focusing; D051379:Mice; D008815:Mice, Inbred Strains; D008970:Molecular Weight; D010587:Phagocytosis
chemical_list: D000942:Antigens, Bacterial