title: Interaction of synthetic peptide octarphin with human blood lymphocytes.
abstract: The synthetic peptide octarphin (TPLVTLFK, fragment 12-19 of β-endorphin), a selective agonist of nonopioid β-endorphin receptor, was prepared with specific activity 28 Ci/mmol. The binding of [3H]octarphin to T and B lymphocytes isolated from the blood of donors was studied. It was found that [3H]octarphin binds both to T and B cells with high affinity: Kd = 3.0 ± 0.2 and 3.2 ± 0.3 nM, respectively. The specific binding of [3H]octarphin to T and B lymphocytes was competitively inhibited by unlabeled β-endorphin (Ki = 1.9 ± 0.2 and 2.2 ± 0.3 nM, respectively) and was not inhibited by unlabeled naloxone, [Met(5)]enkephalin, [Leu(5)]enkephalin, α-endorphin, and γ-endorphin. Thus, T and B lymphocytes of human blood possess a nonopioid β-endorphin receptor whose binding is provided by the fragment 12-19 (the octarphin sequence).
authors.affiliation: Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
authors.forename: Yu N
authors.initials: YN
authors.lastname: Nekrasova
authors.forename: Yu A
authors.initials: YA
authors.lastname: Zolotarev
authors.forename: E V
authors.initials: EV
authors.lastname: Navolotskaya
mesh_terms: D001402:B-Lymphocytes / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011957:Receptors, Opioid / Q000819:agonists; D013601:T-Lymphocytes / Q000737:chemistry / Q000378:metabolism*
chemical_list: D009842:Oligopeptides; D011957:Receptors, Opioid; C555005:octarphin