beta-Endorphin-like peptide SLTCLVKGFY is a selective agonist of nonopioid beta-endorphin receptor.
It has been found that beta-endorphin (beta-END) and a synthetic beta-END-like decapeptide Ser-Leu-Thr-Cys-Leu-Val-Lys-Gly-Phe-Tyr (termed immunorphin, IMN) corresponding to the sequence 364-373 of human IgG heavy chain stimulate Con A-induced proliferation of T lymphocytes from the blood of healthy donors. [Met(5)]enkephalin ([Met(5)]ENK) and an antagonist of opioid receptors naloxone (NAL) tested in parallel were not active. The stimulating effect of beta-END and IMN on T lymphocyte proliferation was not inhibited by NAL. Studies on receptor binding of (125)I-labeled IMN to T lymphocytes revealed that it binds with high affinity to NAL-insensitive binding sites (K(d) = 7.0 +/- 0.3 nM). Unlabeled beta-END completely inhibited the specific binding of (125)I-labeled IMN to NAL-insensitive binding sites on T lymphocytes (K(i) = 1.1 +/- 0.2 nM). Thus, beta-END and IMN bind to common NAL-insensitive binding sites on T lymphocytes and enhance Con A-induced proliferation of these cells.
Navolotskaya
E V
EV
Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Science Avenue, 6, Pushchino, Moscow Region, 142290, Russia. navolots@fibkh.serpukhov.su
Zargarova
T A
TA
Malkova
N V
NV
Krasnova
S B
SB
Zav'yalov
V P
VP
Lipkin
V M
VM
D000595:Amino Acid Sequence; D018712:Analgesics, Non-Narcotic / Q000819:agonists*; D001667:Binding, Competitive / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects; D003208:Concanavalin A / Q000494:pharmacology; D006801:Humans; D007127:Immunoglobulin Constant Regions; D007142:Immunoglobulin gamma-Chains; D007457:Iodine Radioisotopes / Q000737:chemistry; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D011957:Receptors, Opioid / Q000819:agonists* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D001615:beta-Endorphin / Q000494:pharmacology
D018712:Analgesics, Non-Narcotic; D007127:Immunoglobulin Constant Regions; D007142:Immunoglobulin gamma-Chains; D007457:Iodine Radioisotopes; D009842:Oligopeptides; D010446:Peptide Fragments; D011957:Receptors, Opioid; C445661:immunorphin; D003208:Concanavalin A; D001615:beta-Endorphin