Characterization of the bombesin receptor on mouse pancreatic acini by chemical cross-linking
- National Institutes of Health, Bethesda, MD (USA)
Bombesin (BN), gastrin-releasing peptide (GRP) and GRP(18-27) (neuromedin C) were equipotent and 30-fold more potent than neuromedin B (NMB) in inhibiting binding of {sup 125}I-GRP to and in stimulating amylase release from mouse pancreatic acini. In the present study we used {sup 125}I-GRP and chemical cross-linking techniques to characterize the mouse pancreatic BN receptor. After binding of {sup 125}I-GRP to membranes, and incubation with various chemical cross-linking agents, cross-linked radioactivity was analyzed by SDS-PAG electrophoresis and autoradiography. With each of 4 different chemical cross-linking agents, there was a single broad polypeptide band of Mr 80,000. Cross-linking did not occur in the absence of the cross-linking agent. Cross-linking was inhibited only by peptides that interact with the BN receptor such as GRP, NMB, GRP(18-27) or BN. Dose-inhibition curves for the ability of BN or NMB to inhibit binding of {sup 125}I-GRP to membranes or cross-linking to the 80,000 polypeptide demonstrated for both that BN was 15-fold more potent than NMB. The apparent molecular weight of the cross-linked polypeptide was unchanged by adding dithiothreitol. N-Glycanase treatment reduced the molecular weight of the cross-linked peptide to 40,000. The present results indicate that the BN receptor on mouse pancreatic acinar cell membranes resembles that recently described on various tumor cells in being a single glycoprotein with a molecular weight of 76,000. Because dithiothreitol had no effect, this glycoprotein is not a subunit of a larger disulfide-linked structure.
- OSTI ID:
- 5803192
- Journal Information:
- Peptides (Fayetteville, New York); (USA), Vol. 11:6; ISSN 0196-9781
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
PEPTIDES
RECEPTORS
CHEMICAL COMPOSITION
AMYLASE
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
CELL MEMBRANES
CROSS-LINKING
ELECTROPHORESIS
IN VITRO
MICE
MOLECULAR WEIGHT
PANCREAS
REAGENTS
ANIMALS
BODY
CELL CONSTITUENTS
CHEMICAL REACTIONS
DIGESTIVE SYSTEM
ENDOCRINE GLANDS
ENZYMES
GLANDS
GLYCOSYL HYDROLASES
HYDROLASES
KINETICS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
O-GLYCOSYL HYDROLASES
ORGANIC COMPOUNDS
ORGANS
POLYMERIZATION
PROTEINS
REACTION KINETICS
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques