title: Immunoprotective activity of capsular polysaccharide in Klebsiella pneumoniae ribosomal preparations does not involve ribonucleic acid.
abstract: Two peaks were obtained by cesium chloride density gradient ultracentrifugation of Klebsiella pneumoniae ribosomal preparations. Peak I contained capsular polysaccharide, lipopolysaccharide, protein, and less than 0.5% ribonucleic acid. Peak II consisted mainly of ribonucleic acid, with low amounts of protein and capsular polysaccharide. Expressed as capsular polysaccharide content, the 50% protective dose of peak I and of nonfractionated ribosomal preparations was nearly constant (2.6 and 1.2 ng, respectively). Since peak I contained less than 0.5% ribonucleic acid, these results provide evidence that ribosomal ribonucleic acid is not required for protection of mice by K. pneumoniae capsular polysaccharide which contaminates ribosomal preparations.
mesh_terms: D000818:Animals; D007114:Immunization; D007710:Klebsiella Infections / Q000276:immunology*; D007711:Klebsiella pneumoniae / Q000276:immunology*; D051379:Mice; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012329:RNA, Bacterial / Q000276:immunology*; D012335:RNA, Ribosomal / Q000276:immunology*; D012270:Ribosomes / Q000276:immunology
chemical_list: D011135:Polysaccharides, Bacterial; D012329:RNA, Bacterial; D012335:RNA, Ribosomal