Open AccessEvidence for Procollagen, a Biosynthetic Precursor of Collagen
Author(s) -
Garland Bellamy,
Paul Börnstein
Publication year - 1971
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.68.6.1138
Subject(s) - procollagen peptidase , calvaria , biochemistry , hydroxyproline , chemistry , incubation , amino acid , proline , in vitro , microbiology and biotechnology , biology
Incubation of rat calvaria for short times in the presence of a labeled amino acid revealed the existence of a collagen fraction (procollagen) that functions as a biosynthetic precursor of collagen. Procollagen contains an α1-like chain (pre-α1) that elutes earlier from CM-cellulose than does rat-bone α1 and has a molecular weight, estimated by acrylamide gel electrophoresis, of 120,000. A time-dependent conversion of pre-α1 to α1 was demonstrated by incubation of calvaria for periods varying from 9 to 60 min and by a pulse-chase experiment. Limited cleavage of procollagen with pepsin resulted in a molecule with a chain resembling α1 in chromatographic properties, molecular weight, and relative hydroxyproline and proline contents. Thus, conversion of procollagen to collagen is likely to occurin vivo by a proteolytic mechanism. The additional peptide sequences in procollagen may serve to initiate chain association in triple-helix formation, to facilitate molecular transport, and to inhibit intracellular fibrogenesis.