Isolation of a large glycopeptide from cartilage procollagen by collagenase digestion and evidence indicating the presence of glucose, galactose and mannose in the peptide.

Digestion of cartilage procollagen, pro-α1(II), with bacterial collagenase followed by fractionation of Sephadex G-150 yielded a large glycopeptide (molecular weight 13,200) which could not be demonstrated in a similarly prepared digest of α1(II) chain. Isotopic studies suggested that this glycopeptide contained, in addition to glucose and galactose, mannose, a sugar that is not found in the authentic α-chain of cartilage. The results imply that in pro-α1(II) there is a glycopeptide region differing from the α1(II) chain in amino acid composition and also in the type of carbohydrates attached.