Interaction of synthetic peptide octarphin with human blood lymphocytes

• Published in: Biochemistry (Moscow) Vol. 78; no. 3; pp. 309 - 313
• Main Authors: Nekrasova, Yu. N., Zolotarev, Yu. A., Navolotskaya, E. V.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01.03.2013; Springer; Springer Nature B.V
• Subjects: B-Lymphocytes - chemistry; B-Lymphocytes - metabolism; Beta-endorphin; Binding sites; Biochemistry; Biomedical and Life Sciences; Biomedicine; Bioorganic Chemistry; Blood; Health aspects; Humans; Kinetics; Life Sciences; Lymphocytes; Microbiology; Naloxone; Oligopeptides - chemical synthesis; Oligopeptides - chemistry; Oligopeptides - metabolism; Peptides; Protein Binding; Receptors, Opioid - agonists; T-Lymphocytes - chemistry; T-Lymphocytes - metabolism; Russia; naloxone; peptide; β-endorphin; lymphocytes; receptors
• ISSN: 0006-2979; 1608-3040
• DOI: 10.1134/S0006297913030140

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 [ 3 H]octarphin to T and B lymphocytes isolated from the blood of donors was studied. It was found that [ 3 H]octarphin binds both to T and B cells with high affinity: K d = 3.0 ± 0.2 and 3.2 ± 0.3 nM, respectively. The specific binding of [ 3 H]octarphin to T and B lymphocytes was competitively inhibited by unlabeled β-endorphin ( K i = 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).