RAT FIBROSARCOMA AS A SOURCE OF STABLE COPOLYMER OF TYPE-I AND TYPE-III COLLAGENS

During conventional procedures for the extraction of collagen from rat fibrosarcoma it was observed that a significant fraction of the acid- soluble collagen remained insoluble when subsequently fractionated at neutral pH. Analysis of this collagenous component, using amino acid a nalysis, cyanogen bromide peptide mapping, proteinase susceptibility a nd the action of denaturing and reducing agents, revealed different pr operties when compared to other collagen species. The results indicate that the tumour collagen fraction is probably a stable complex of typ e I and III collagens. This native collagen heteropolymer represented approximately 18% of the total collagen from rat fibrosarcoma and as s uch provides a unique natural source of this collagen complex for furt her analytical studies.