TYPE-I COLLAGEN AND FIBRONECTIN SYNTHESIS BY RETROCORNEAL FIBROUS MEMBRANE

  • 1 January 1982
    • journal article
    • research article
    • Vol. 22  (2) , 200-212
Abstract
Primary cultures obtained from the experimentally induced [rabbit] retrocorneal fibrous membrane synthesized and secreted into the medium mainly type I procollagen. This collagen was characterized afer limited pepsin treatment and identified as type I collagen by the following criteria: it contained 2 .alpha.1 chains and 1 .alpha.2 chain, its sedimentation behavior was identical to that of type I collagen from skin; and its peptide map after limited proteolysis with Staphylococcus aureus V8 protease was identical to that of type I collagen. The medium contained procollagen I, which was converted into .alpha. size chains by limited pepsin treatment; the cellular fraction contained type I collagen already processed to its end product. Type III collagen and basement membrane collagen were present as minor components in this system. Fibronectin, 1 of the major glycoproteins in extracellular matrices, was synthesized and secreted into the medium. Normal corneal endothelial cells produce mainly basement membrane collagen.