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[ 125 I]orphanin FQ/nociceptin binding in Raji cells
Author(s) -
Hom Judith S.H.,
Goldberg Ira,
Mathis John,
Pan YingXian,
Brooks Andrew I.,
RyanMoro Jennifer,
Scheinberg David A.,
Pasternak Gavril W.
Publication year - 1999
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/(sici)1098-2396(19991201)34:3<187::aid-syn3>3.0.co;2-a
Subject(s) - nociceptin receptor , raji cell , chemistry , receptor , microbiology and biotechnology , cell culture , binding site , cell , biochemistry , opioid , biology , opioid peptide , genetics
Western blots using an antibody which recognizes the orphanin FQ/nociceptin (OFQ/N) receptor reveals a band at approximately 69 kD in several cell lines, including the Raji human B cell lymphoma cell line. RT‐PCR confirms the presence of this receptor in the Raji cells. Binding studies revealed a high affinity [ 125 I][Tyr 14 ]OFQ/N site in the Raji cells. The affinity of [ 125 I][Tyr 14 ]OFQ/N in the Raji cells (K D 68.4 pM) was similar to that in the transfected receptor (K D 36.7 pM). Its selectivity profile also was quite similar. OFQ/N competed binding quite potently (K i 65 pM), as did [Tyr 14 ]OFQ/N (K i 33 pM). Traditional opioids displayed no appreciable affinity for the binding at any concentration examined, with the exception of naloxone benzoylhydrazone, which had only a very modest affinity. The receptors in the Raji cells were functionally active. OFQ/N inhibited forskolin‐stimulated cyclase by 72% with an IC 50 value of approximately 1 nM. Synapse 34:187–191, 1999. © 1999 Wiley‐Liss, Inc.