Identification of disulphide‐bonded type X procollagen polypeptides in embryonic chick chondrocyte culture

Abstract
A high‐M r (M r 120000), disulphide‐bonded collagenous polypeptide was observed to co‐purify with the proα1(X) chain during isolation of cartilage collagens from culture medium of embryonic chick tibiotarsal chondrocytes. This high‐M r polypeptide was subsequently shown by two‐dimensional SDS‐PAGE and peptide mapping to represent a dimer of the proα1(X) chain of type X collagen linked by disulphide bonding in the non‐collagenous domains.