STRUCTURE OF ANTIGENIC DETERMINANTS IN THE N-TERMINAL REGION OF DERMATOSPARACTIC SHEEP PROCOLLAGEN TYPE-I

About half of the rabbit antisera raised against type-I procollagen, pα1(I) chain or nonreduced procollagen peptides reacted in a radioimmunoassay with the reduced form of peptide Col 1, which comprises the whole non-collagenous region at the N-terminus of procollagen. Proteolytic framents prepared from reduced peptide Col 1 were still effective inhibitors of the antibodies and allowed the localization of two antigenic determinants. The antigenically active regions have the sequences <Glu-Glu-Glu-Gly-Gln-Gln-Glu and Gly-Asp-Thr-Gly-Pro-Arg, and are located at the N- and C-termini of the peptide respectively. Antibodies raised against reduced peptide Col 1 bind to a determinant localized in a different region of the peptide.