Evidence for glycoprotein components of the hepatocellular bile acid transporter.
The hepatocellular transporter, responsible for the uptake of bile acids and some foreign substances, can be shown to contain carbohydrate moieties. The hepatocellular uptake of cholate and phallotoxin is immediately inhibited by addition of wheat-germ agglutinin. Concanavalin A and lentil lectin reduce the uptake in a time-dependent manner. Apparently sialic acids or N-acetylglucosamine residues are involved in the translocation process. Polypeptides (Mr 50,000, 54,000) of the above transport system, identified by affinity labeling with [3H]isothiocyanatobenzamido cholate and [3H2]diisothiocyano-1,2-diphenylethane-2,2'-disulfonic acid, are heterogenously glycosylated. Binding of 80-90% of the 54, 50 kDa polypeptides to all immobilized lectins tested suggests that both high-mannose and complex type oligosaccharides with fucose and terminal sialic acid residues occur as carbohydrate chains. A 67 kDa labeled polypeptide is not glycosylated. Pilot experiments for purification of the above glycosylated membrane proteins on concanavalin A, lentil lectin and wheat-germ lectin columns are described. However, lectin affinity chromatography is not suitable as a one-step purification procedure for the labeled polypeptides.
Ziegler
K
K
Institut für Pharmakologie und Toxikologie, Fachbereich Veterinärmedizin, Justus Liebig Universität, Giessen, F.R.G.
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000031:analogs & derivatives*; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D000117:Acetylglucosamine / Q000378:metabolism; D000345:Affinity Labels; D000546:Amanitins / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000032:analysis / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D019826:Cholic Acid; D002793:Cholic Acids / Q000378:metabolism; D002846:Chromatography, Affinity; D003208:Concanavalin A / Q000378:metabolism / Q000494:pharmacology; D006023:Glycoproteins / Q000032:analysis / Q000378:metabolism*; D006031:Glycosylation; D006913:Hydroxysteroid Dehydrogenases; D017879:Isothiocyanates; D037102:Lectins / Q000378:metabolism / Q000494:pharmacology; D008099:Liver / Q000378:metabolism*; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000378:metabolism; D008970:Molecular Weight; D037121:Plant Lectins; D051381:Rats; D012794:Sialic Acids / Q000378:metabolism; D013861:Thiocyanates / Q000378:metabolism; D014909:Wheat Germ Agglutinins / Q000378:metabolism / Q000494:pharmacology; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D000117:Acetylglucosamine; D000345:Affinity Labels; D000546:Amanitins; D002352:Carrier Proteins; D019826:Cholic Acid; D002793:Cholic Acids; D003208:Concanavalin A; D006023:Glycoproteins; D006913:Hydroxysteroid Dehydrogenases; D017879:Isothiocyanates; D037102:Lectins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D037121:Plant Lectins; D012794:Sialic Acids; D013861:Thiocyanates; D014909:Wheat Germ Agglutinins; C037643:bile acid binding proteins; C033619:lentil lectin; C018358:phallotoxin; C018564:dihydro-DIDS; C041686:3'-isothiocyanatobenzamidecholic acid; C435496:AKR1C2 protein, human; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific)