Some Biochemical and Serologic Properties of the Pneumococcal C Polysaccharide.

Abstract

Summary The serologically active C polysaccharide of pneumococcus was isolated as a substance fairly homogeneous in ultracentrifuge (S_20w = 3) and on paper electrophoresis consisting of glucosamine, galactosamine, and glucose, and a uridine nucleotide composed of UDP, muramic acid and a peptide consisting chiefly of alanine, glycine, glutamic and diaminopimelic acids with a trace of serine. It could be precipitated by streptomycin and redissolved in 1 M NaCl. Removal of the uridine nucleotide by mild acid hydrolysis destroyed the serological activity and the uridine nucleotide removed was capable of inhibiting the C-CRP reaction, as was uridine monophosphate in a concentration of 1 mg/ml. It is suggested that the uridine nucleotide portion of the C substance is responsible for its complexing with human CRP.