Abstract
Preparations of mucopeptide were solubilized from formamide-extracted residues of groups A and B streptococcal cell walls by sonication and purified by column chromatography on Sephadex. Other preparations were made by digestion of particulate mucopeptide with lysozyme and Streptomyces albus muramidase. Analysis of these materials showed chemical similarity and a range of molecular size estimated to be greater than 20 × 106 to less than 5 × 103. The larger components reacted serologically as precipitinogens and the smaller as haptenic inhibitors. Mucopeptide preparations of larger molecular size produced migration inhibition reactions (MIR) with peritoneal cells from non-sensitized rats and guinea pigs. In general, MIR and dermonecrotic reactions decreased with decreasing molecular size. Anti-mucopeptide antibody only slightly reduced mucopeptide-induced MIR. Isolation of a migration inhibition factor by Sephadex chromatography from supernatants of cell cultures incubated with mucopeptide was unsuccessful. Stimulation of cells with Bayol F was required to produce cells susceptible to MIR. Under the experimental conditions for demonstration of MIR, mucopeptide did not directly cause lysis or reduce viability of the peritoneal cells used in the test system.