title: Binding of synthetic peptide TPLVTLFK to nonopioid beta-endorphin receptor on rat brain membranes.
abstract: The synthetic peptide TPLVTLFK corresponding to the sequence 12-19 of beta-endorphin (referred to as octarphin) was found to bind to high-affinity naloxone-insensitive binding sites on membranes isolated from the rat brain cortex (K(d) = 2.6 +/- 0.2 nM). The binding specificity study revealed that these binding sites were insensitive not only to naloxone but also to alpha-endorphin, gamma-endorphin, [Met(5)]enkephalin, and [Leu(5)]enkephalin, as well. The [(3)H]octarphin specific binding with brain membranes was inhibited by unlabeled beta-endorphin (K(i) = 2.4 +/- 0.2 nM) and a selective agonist of nonopioid beta-endorphin receptor decapeptide immunorphin SLTCLVKGFY (K(i) = 2.9 +/- 0.2 nM). At the same time, unlabeled octarphin completely (by 100%) inhibited the specific binding of [(3)H]immunorphin with membranes (K(i) = 2.8 +/- 0.2 nM). Thus, octarphin binds with a high affinity and specificity to nonopioid receptor of beta-endorphin on rat brain cortex membranes.
authors.affiliation: Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Pushchino, Moscow Region, Russia.
authors.forename: Yuliia N
authors.initials: YN
authors.lastname: Nekrasova
authors.forename: Vladimir B
authors.initials: VB
authors.lastname: Sadovnikov
authors.forename: Yury A
authors.initials: YA
authors.lastname: Zolotarev
authors.forename: Elena V
authors.initials: EV
authors.lastname: Navolotskaya
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D011957:Receptors, Opioid / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001615:beta-Endorphin / Q000235:genetics / Q000378:metabolism
chemical_list: D010455:Peptides; D011957:Receptors, Opioid; D001615:beta-Endorphin