POLYSACCHARIDE-PEPTIDE COMPLEXES FROM SERRATIA MARCESCENS CELLS

Abstract

Determinations were made of the chemical composition and antitumor properties of several polysaccharide fractions obtained by high speed centrifugation of aqueous extracts of the cells of Serratia marcescens following phenol extraction and trypsin digestion. The use of methods that ensured complete removal of lipid gave polysaccharides containing firmly bound amino acid residues. These were highly effective in causing complete regression of well established solid tumors in mice. The products derived primarily from the cell wall were more potent than the polysaccharides of extracellular and cytoplasmic origins. Extensive differences were also noted in the chemical composition of the polysaccharide complexes isolated from the two sources.