The canine renal parathyroid hormone receptor is a glycoprotein: characterization and partial purification.
Covalent labeling of the canine renal parathyroid hormone receptor with [125I]bPTH(1-34) reveals several major binding components that display characteristics consistent with a physiologically relevant adenylate cyclase linked receptor. Through the use of the specific glycosidases neuraminidase and endoglycosidase F and affinity chromatography on lectin-agarose gels, we show here that the receptor is a glycoprotein that contains several complex N-linked carbohydrate chains consisting of terminal sialic acid and penultimate galactose in a beta 1,4 linkage to N-acetyl-D-glucosamine. No high mannose chains or O-linked glycans appear to be present. The peptide molecular weight of the deglycosylated labeled receptor is 62,000 [or 58,000 if the mass of bPTH(1-34) is excluded]. The binding of [125I]bPTH(1-34) to the receptor is inhibited in a dose-dependent fashion by wheat-germ agglutinin, but not by either succinylated wheat-germ agglutinin or Ricinus communis lectin, suggesting that terminal sialic acid may be involved in agonist binding. A combination of lectin affinity chromatography and immunoaffinity chromatography affords a 200-fold purification of the covalently labeled receptor.
Karpf
D B
DB
Endocrine Unit, Veterans Administration Medical Center, San Francisco, California.
Arnaud
C D
CD
King
K
K
Bambino
T
T
Winer
J
J
Nyiredy
K
K
Nissenson
R A
RA
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002846:Chromatography, Affinity; D004285:Dogs; D006023:Glycoproteins / Q000302:isolation & purification / Q000378:metabolism*; D006026:Glycoside Hydrolases; D007672:Kidney Cortex / Q000378:metabolism*; D007700:Kinetics; D037102:Lectins; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D008970:Molecular Weight; D009439:Neuraminidase; D010281:Parathyroid Hormone / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000302:isolation & purification / Q000378:metabolism*; D018016:Receptors, Parathyroid Hormone
D006023:Glycoproteins; D037102:Lectins; D010281:Parathyroid Hormone; D011956:Receptors, Cell Surface; D018016:Receptors, Parathyroid Hormone; D006026:Glycoside Hydrolases; D009439:Neuraminidase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase