Carbohydrate moieties of the. cap alpha. /sub 1/-adrenergic receptor (. cap alpha. /sub 1/-R): complex type glycosylation of N-linked oligosaccharides

Conference · Fri May 01 04:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6029051

Sawutz, D G; Lanier, S M; Warren, C D; Homcy, C J; Graham, R M

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-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 46:6
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
AUTONOMIC NERVOUS SYSTEM AGENTS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
CARBOHYDRATES
CHEMICAL COMPOSITION
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
ENZYMES
GLYCOSYL HYDROLASES
HYDROLASES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
MEMBRANE PROTEINS
METABOLISM
NUCLEI
ODD-EVEN NUCLEI
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
PROTEINS
RADIOISOTOPES
RECEPTORS
SACCHARIDES
SYMPATHOMIMETICS