High-affinity receptors for peptides of the bombesin family in Swiss 3T3 cells
Gastrin-releasing peptide (GRP) labeled with /sup 125/I at tyrosine-15 (/sup 125/I-GRP) binds to intact quiescent Swiss 3T3 cells in a specific and saturable manner. Scatchard analysis indicates the presence of a single class of high-affinity binding sites of Kd = 0.5 X 10(-9) M and a value for the number of sites per cell of about 100,000. /sup 125/I-GRP binding was not inhibited by other mitogens for these cells, and cell lines that are mitogenically unresponsive to GRP do not exhibit specific GRP binding. Structure-activity relationships show a close parallel between the ability of a range of GRP-related peptides to both inhibit GRP binding and to stimulate mitogenesis. Further, GRP binding is selectively blocked in a competitive fashion by a novel bombesin antagonist, (D-Arg1, D-Pro2, D-Trp7,9, Leu11) substance P. In addition, this compound selectively inhibits GRP and bombesin-induced mitogenesis. These results demonstrate that the mitogenic response of Swiss 3T3 cells to peptides of the bombesin family is mediated by a class of receptors distinct from those of other mitogens for these cells.
- OSTI ID:
- 5692004
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 22
- Country of Publication:
- United States
- Language:
- English
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Characterization of a bombesin receptor on Swiss mouse 3T3 cells by affinity cross-linking
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PEPTIDES
BIOCHEMICAL REACTION KINETICS
RECEPTORS
AFFINITY
DNA
FIBROBLASTS
IODINE 125
MICE
MITOGENS
STRUCTURE-ACTIVITY RELATIONSHIPS
TRACER TECHNIQUES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
NUCLEI
NUCLEIC ACIDS
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RODENTS
SOMATIC CELLS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques