Identification of the binding subunit of the D/sub 1/-dopamine receptor by photoaffinity crosslinking

Conference · Sat Mar 01 04:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5497996

Amlaiky, N; Berger, J G; Chang, W; McQuade, R D; Caron, M G

A derivative of the potent D/sub 1/ antagonist SCH-23390 has been synthesized. This compound, (R,S)-1-(m-aminophenyl)-7-chloro-8-hydroxy-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine (SCH-38548), has been radioiodinated by a chloramine T procedure yielding 3 radioiodinated products. One of these separated isomers (R/sub f/ = 0.35; CH/sub 2/Cl/sub 2/:MEOH:TEA; 82.5:17.5:0.1 on TLC) binds reversibly to rat striatal membranes with high affinity (K/sub D/ approx. 80 pM) appropriate stereoselectivity and D/sub 1/-dopaminergic specificity. (/sup 125/I)SCH-38548 can be covalently incorporated into a peptide of M/sub r/ approx. 72,000 using the heterobifunctional crosslinking reagent N-succinimidyl-6-(4'-azido-2'-nitro-phenylamino) hexanoate. Covalent incorporation of (/sup 125/I) SCH-38548 into the M/sub r/ approx. 72,000 peptide can be blocked by dopaminergic agents with D/sub 1/-dopaminergic specificity (for agonists: SKF 38393 > apomorphine > dopamine; for antagonists: SCH-23390 > cis-flupentixol >>> trans-flupentixol). The D/sub 1/-dopaminergic selectivity and specificity of the labeling was further demonstrated by the fact that other antagonists such as domperidone, ketanserin, phentolamine and alprenolol did not compete for the covalent labeling of the M/sub r/ approx. 72,000 peptide. This new radioligand should be useful in the molecular characterization of the D/sub 1/-dopaminergic receptor from various sources.

• Research Organization: Duke Univ. Medical Center, Durham, NC
• OSTI ID: 5497996
• Report Number(s): CONF-8604222-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:3
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL REACTIONS
COVALENCE
CROSS-LINKING
DAYS LIVING RADIOISOTOPES
DOPAMINE
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLING
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NEUROREGULATORS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDES
PHENOLS
POLYMERIZATION
POLYPHENOLS
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SYMPATHOMIMETICS
TRACER TECHNIQUES
VERTEBRATES