Biosynthesis of basement membrane collagen by rabbit corneal endothelium in vitro.
The synthesis of collagen has been demonstrated in endothelial cells of Descemet's membrane isolated from rabbit cornea. Incorporation of [14C]proline and [14C]lysine into nondialyzable protein was measured in the medium and cell fraction after incubating Descemet's membrane for up to 5 hours. In the [14C]collagen synthesized by the endothelium, 15% of the hydroxy[14C]proline was present as the 3-isomer. About 98% of the hydroxy[14C]lysine in the 14C-labeled-protein found in the medium was glycosylated; 95% of the glycosylated hydroxy[14C]lysine was in the form of the disaccharide glucosyl-galactosyl-hydroxy[14C]lysine. Time course experiments with [14C]proline indicated that there was a delay of about 60 min before significant amounts of [14C]collagen were secreted into the medium. The initial polypeptides of [14C]collagen synthesized by the corneal endothelium had an apparent molecular weight of 155,000. The chemical and physical properties of the [14C]collagen synthesized by rabbit corneal endothelium are consistent with those of basement membrane collagen synthesized by other cell types.
D000818:Animals; D001485:Basement Membrane / Q000378:metabolism*; D003094:Collagen / Q000096:biosynthesis*; D003315:Cornea / Q000378:metabolism*; D004727:Endothelium / Q000378:metabolism; D006909:Hydroxyproline / Q000378:metabolism; D007700:Kinetics; D008239:Lysine / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D011817:Rabbits
D003094:Collagen; D011392:Proline; D008239:Lysine; D006909:Hydroxyproline