Open AccessCathepsin D-mediated processing of procollagen: lysosomal enzyme involvement in secretory processing of procollagen.
Author(s) -
Donald L. Helseth,
Arthur Veis
Publication year - 1984
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.81.11.3302
Subject(s) - pepstatin , procollagen peptidase , cathepsin , biochemistry , cathepsin o , chemistry , cathepsin l1 , protein precursor , cathepsin a , cleavage (geology) , cathepsin h , cathepsin d , microbiology and biotechnology , leupeptin , cathepsin e , cathepsin c , cathepsin l , enzyme , biology , protease , paleontology , fracture (geology)
The proteolytic removal of the extension COOH-terminal propeptide from procollagen has been examined in vitro. A crude enzyme activity was identified in a whole-chicken-embryo extract that acted at acid pH and appeared to be similar to one identified previously [Davidson, J. M., McEneany , L. S. G. & Bornstein , P. (1979) Eur. J. Biochem. 100, 551-558]. This activity was inhibitable by pepstatin but not by leupeptin, suggesting that it might be cathepsin D. Cathepsin D was purified 907-fold from chicken livers by affinity chromatography on pepstatin-aminohexyl-Sepharose 4B and was found to remove the COOH propeptides from procollagen. At pH 6.0, the site of cleavage appeared to shift from the COOH telopeptide to the COOH telopeptide/propeptide junction, based upon the difference in electrophoretic migration of the cleavage products, although determining the actual cleavage site will require end-group analysis. A model for the involvement of cathepsin D in the in vivo processing of procollagen is presented.