Carbohydrate moieties of the. cap alpha. /sub 1/-adrenergic receptor (. cap alpha. /sub 1/-R): complex type glycosylation of N-linked oligosaccharides
The binding subunit of the ..cap alpha../sub 1/-R has been identified as a M/sub r/ = 80,000 peptide in several tissues. Adsorption of the ..cap alpha../sub 1/-R to a WGA lectin-agarose resin suggests that the receptor protein is glycosylated. In this study, they investigated the nature of the carbohydrate linkage to the ..cap alpha../sub 1/-R peptide. The ..cap alpha../sub 1/-R in DDT/sub 1/ MF-2 whole cells was photolabeled with /sup 125/I-azido-prazosin, the cells were lysed in the presence of DNAase, and cell membranes were treated with exo- and endoglycohydrolases prior to SDS-PAGE and autoradiography. Removal of terminal sialic acid residues by neuraminidase decreased the receptor M/sub r/ by 4000; however ..cap alpha..-mannosidase was without effect indicating complex type glycosylation of the receptor-protein. Similar results were observed for the rat hepatic membrane ..cap alpha../sub 1/-R. After deglycosylation of N-linked carbohydrates at asparagine residues by N-glycanase a specifically labeled peptide at a M/sub r/ = 50,000 was observed in DDT/sub 1/ MF-2 cells. Treatment of photolabeled ..cap alpha../sub 1/-R with endo-..beta..-N-acetylglucosaminidase F or H had no effect. These results indicate that the ..cap alpha../sub 1/-R is heavily glycosylated, the major oligosaccharide moiety being of the complex type, N-linked to asparagine residues and that the peptide backbone has a M/sub r/ < 50,000. By contrast, the ..cap alpha../sub 2/-R has a peptide backbone of M/sub r/ = 38,000 and N-linked oligosaccharides of the hybrid type.
- Research Organization:
- Massachusetts General Hospital, Boston
- OSTI ID:
- 6029051
- Report Number(s):
- CONF-870644-; TRN: 87-037166
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
- Country of Publication:
- United States
- Language:
- English
Similar Records
Complementary DNA and derived amino acid sequence of the. cap alpha. subunit of human complement protein C8: evidence for the existence of a separate. cap alpha. subunit messenger RNA
Role of a guanine nucleotide-binding protein in. cap alpha. /sub 1/-adrenergic receptor-mediated Ca/sup 2 +/ mobilization in DDT/sub 1/ MF-2 cells
Related Subjects
OLIGOSACCHARIDES
METABOLISM
RECEPTORS
CHEMICAL COMPOSITION
SYMPATHOMIMETICS
AUTORADIOGRAPHY
ELECTROPHORESIS
GLYCOSYL HYDROLASES
IODINE 125
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
CARBOHYDRATES
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
HYDROLASES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
MEMBRANE PROTEINS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PROTEINS
RADIOISOTOPES
SACCHARIDES
550201* - Biochemistry- Tracer Techniques