Identification of the binding subunit of the sigma-type opiate receptor by photoaffinity labeling with 1-(4-azido-2-methyl(6-/sup 3/H)phenyl)-3-(2-methyl(4,6-/sup 3/H)phenyl)guanidine

Journal Article · Fri Apr 01 00:00:00 EST 1988 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.85.8.2844· OSTI ID:6143401

Kavanaugh, M P; Tester, B C; Scherz, M W; Keana, J F.W.; Weber, E

The sigma-type opiate receptor is a distinct binding site in the brain that may mediate some of the psychotomimetic effects caused by benzomorphan opiates and phencyclidine in humans. The authors have developed a synthetic, highly selective ligand for this receptor, 1,3-di-o-tolylguanidine (DTG). To identify the binding protein(s) of the sigma receptor, they have now synthesized a radiolabeled azide derivative of DTG, ((/sup 3/H)N/sub 3/DTG). In guinea pig brain membrane binding assays conducted in the dark, (/sup 3/H)N/sub 3/DTG bound reversibly, selectively, and with high affinity to sigma receptors. The drug specificity profile of reversible (/sup 3/H)-N/sub 3/DTG binding was identical to that of (/sup 3/H)DTG and /sup 3/H-labeled (+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine binding indicating that (/sup 3/H)N/sub 3/DTG is a selective sigma receptor ligand. Guinea pig brain membranes were photoaffinity-labeled with (/sup 3/H)N/sub 3/DTG. NaDodSO/sub 4//PAGE of detergent-solubilized membrane extract identified a single 29-kDa radioactive band. Sepharose Cl-6B gel chromatography of photolabeled brain membranes solubilized with the nondenaturing detergent sodium cholate showed a radioactive complex with a Stoke's radius of 4.6 nm (M/sub r/, 150,000) that may represent the intact sigma receptor complex. NaDodSO/sub 4//PAGE of this complex showed the radiolabeled material was a 29-kDa polypeptide that may be binding subunit of the sigma receptor.

• Research Organization: Oregon Health Sciences Univ., Portland (USA)
• OSTI ID: 6143401
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 85:8
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CELL MEMBRANES
CROSS-LINKING
NARCOTICS
RECEPTORS
MOLECULAR STRUCTURE
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
BRAIN
DERIVATIZATION
DOSE-RESPONSE RELATIONSHIPS
GUINEA PIGS
LIGANDS
POLYPEPTIDES
TRITIUM COMPOUNDS
ANIMALS
BODY
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM DEPRESSANTS
CHEMICAL REACTIONS
DRUGS
KINETICS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
POLYMERIZATION
PROTEINS
REACTION KINETICS
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques