Identification and partial characterization of two major proteins of Mr 47,000 synthesized by bovine retinal endothelial cells in culture.
Biosynthetic experiments with cultured bovine retinal endothelial cells have identified a glycoprotein of Mr 47,000 (Gp47) as a major component secreted into the medium. Gp47 is a non-collagenous glycoprotein with a pI of 4.6-5.5, which does not bind to either gelatin-Sepharose or heparin-Sepharose but is retained by concanavalin A-Sepharose. The Mr of this species decreases to approx. 42,000 in the presence of tunicamycin, indicating that it contains asparagine-linked oligosaccharides. A second protein of Mr 47,000 (P47) is present in the cell layer/matrix of these cultured cells. The electrophoretic mobility of P47 remains unaltered when synthesized in the presence of tunicamycin. Peptide-mapping experiments using N-chlorosuccinimide and Staphylococcus aureus V8 proteinase demonstrate that Gp47 and P47 are distinct proteins, and are not related to colligin, a membrane-bound collagen-receptor protein of similar size, or to SPARC, a major secreted product of parietal endodermal cells and sparse cultures of aortic endothelial cells.
Canfield
A E
AE
Department of Biochemistry and Molecular Biology, School of Biological Sciences, University of Manchester, U.K.
Schor
A M
AM
West
D C
DC
Schor
S L
SL
Grant
M E
ME
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D004727:Endothelium / Q000378:metabolism; D005136:Eye Proteins / Q000096:biosynthesis*; D007525:Isoelectric Focusing; D008970:Molecular Weight; D010449:Peptide Mapping; D012160:Retina / Q000378:metabolism*
D005136:Eye Proteins