Common peptide epitopes in glycophorin and the endothelial sialoglycoprotein gp60.
Polyclonal anti-serum made against murine glycophorin gp3 (alpha gp) recognizes the endothelial albumin binding glycoprotein, gp60. In this study, we investigated the nature (peptide vs. carbohydrate) of the common epitope. First, a new technique was developed to remove oligosaccharides from glycoproteins that were first immobilized on filters and then subjected to beta-elimination. When greater than 90% of the glycans of gp60 were removed, alpha gp still recognized gp60 without apparent loss of affinity. Second, we used brefeldin A to accumulate unglycosylated glycophorin precursors in order to affinity-purify peptide-specific alpha gp immuno-globulins; these antibodies recognized gp60. Finally, alpha gp recognized from in vitro translations a 48 kDa putative polypeptide precursor of gp60. These different approaches indicate that gp60 and gp3 have at least one common epitope in their peptide backbones.
Schnitzer
J E
JE
Dept. of Medicine, Univ. Calif.- San Diego School of Medicine, La Jolla 92093-0651.
Ulmer
J B
JB
Palade
G E
GE
D000818:Animals; D000918:Antibody Specificity; D020126:Brefeldin A; D002236:Carbohydrate Conformation; D002241:Carbohydrates / Q000302:isolation & purification; D002417:Cattle; D002460:Cell Line; D003517:Cyclopentanes; D004727:Endothelium / Q000276:immunology; D004730:Endothelium, Vascular / Q000276:immunology; D000939:Epitopes / Q000032:analysis*; D006021:Glycophorins / Q000276:immunology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007106:Immune Sera / Q000276:immunology; D007163:Immunosorbent Techniques; D008297:Male; D051379:Mice; D011134:Polysaccharides / Q000302:isolation & purification; D014176:Protein Biosynthesis; D011498:Protein Precursors / Q000235:genetics; D011506:Proteins / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D012795:Sialoglycoproteins / Q000235:genetics / Q000276:immunology*
D002241:Carbohydrates; D003517:Cyclopentanes; D000939:Epitopes; D006021:Glycophorins; D007106:Immune Sera; D011134:Polysaccharides; D011498:Protein Precursors; D011506:Proteins; D012333:RNA, Messenger; D012795:Sialoglycoproteins; C065610:sialoglycoprotein gp60; D020126:Brefeldin A