title: [Effect of new peptide bioregulators livagen and epitalon on enkephalin-degrading enzymes in human serum].
abstract: The effect of new peptide bioregulators--Livagen (Lys-Glu-Asp-Ala) and Epitalon (Ala-Glu-Asp-Gly)--on endogenous opioid system was studied, particularly, their ability to change the activity of enkephalin-degrading enzymes from serum and interact with opioid receptors of the brain membrane fraction. Enkephalinase activity was assayed in vitro by the rate of 3H-Leu-enkephalin hydrolysis in the presence of the tested peptides. Livagen and Epitalon inhibited enkephalin-degrading enzymes from human serum. Livagen proved to be more efficient also as compared to well-known peptidase inhibitors such as puromycin, leupeptin, and D-PAM. The dose-inhibitory effect curves for Livagen and Epitalon were plotted; their IC50 equaled 20 and 500 microM, respectively. The interaction between the peptides and opioid receptors was estimated using a radioreceptor method with [3H][D-Ala2, D-Leu5]-enkephalin. No interaction was observed between the tested peptides and mu- or delta-opioid receptors of the membrane fraction from the rat brain.
authors.affiliation: Mental Health Research Center, Russian Academy of Medical Sciences, Kashirskoe sh. 34, Moscow, 115522 Russia.
authors.forename: N V
authors.initials: NV
authors.lastname: Kost
authors.forename: O Iu
authors.initials: OIu
authors.lastname: Sokolov
authors.forename: M V
authors.initials: MV
authors.lastname: Gabaeva
authors.forename: Iu A
authors.initials: IuA
authors.lastname: Zolotarev
authors.forename: V V
authors.initials: VV
authors.lastname: Malinin
authors.forename: V Kh
authors.initials: VKh
authors.lastname: Khavinson
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D004743:Enkephalin, Leucine / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004798:Enzymes / Q000097:blood*; D006801:Humans; D066298:In Vitro Techniques; D015260:Neprilysin / Q000378:metabolism; D009841:Oligonucleotides / Q000494:pharmacology*; D009842:Oligopeptides / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D017465:Receptors, Opioid, delta / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D004798:Enzymes; C473185:Livagen; D009841:Oligonucleotides; D009842:Oligopeptides; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D004743:Enkephalin, Leucine; D015260:Neprilysin; C421253:alanyl-glutamyl-aspartyl-glycine