Abstract
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.
Original language | English |
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Pages (from-to) | 121-9 |
Number of pages | 9 |
Journal | The Biochemical journal |
Volume | 246 |
Issue number | 1 |
DOIs | |
Publication status | Published - 15 Aug 1987 |
Keywords
- Animals
- Cattle
- Cells, Cultured
- Chromatography, Affinity
- Electrophoresis, Polyacrylamide Gel
- Endothelium/metabolism
- Eye Proteins/biosynthesis
- Isoelectric Focusing
- Molecular Weight
- Peptide Mapping
- Retina/metabolism