title: Opioid peptides derived from food proteins suppress aggregation and promote reactivation of partly unfolded stressed proteins.
abstract: A new view of the opioid peptides is presented. The potential of small peptides derived from precursor food proteins, to bind to partly unfolded stressed proteins to prevent their irreversible aggregation and inactivation has been demonstrated in various in vitro test systems: dithiothreitol-induced aggregation of alpha-lactalbumin (LA), heat-induced aggregation of alcohol dehydrogenase (ADH), and aggregation and inactivation of bovine erythrocyte carbonic anhydrase (CA) in the process of its refolding after removal of stress conditions. Using dynamic light scattering (DLS), turbidimetry, fluorescence, and circular dichroism measurements protective effects of the synthetic opioid peptides: exorphin C from wheat gluten (Tyr-Pro-Ile-Ser-Leu), rubiscolin-5 from spinach ribulose-bisphosphate-carboxylase/oxygenase (Rubisco) (Tyr-Pro-Leu-Asp-Leu), and hemorphin-6 from bovine hemoglobin (Tyr-Pro-Trp-Thr-Gln-Arg) have been revealed. We have demonstrated the concentration-dependent suppression of light scattering intensity of aggregates of LA and ADH in the presence of the peptides, the population of nanoparticles with higher hydrodynamic radii being shifted to the lower ones, accompanied by an increase in the lag period of aggregation. The presence of the peptides in the refolding solution was shown to assist reactivation of CA and enhance the yield of the CA soluble protein. The results suggest that bioactive food protein fragments may be regarded as exogenous supplements to the endogenous defense mechanisms of the human organism under stress conditions.
authors: A.N. Bakh Institute of Biochemistry, Russian Academy of Sciences, Leninsky Prospect, 33, 119071 Moscow, Russia.
authors: N V
authors: NV
authors: Artemova
authors: Z M
authors: ZM
authors: Bumagina
authors: A S
authors: AS
authors: Kasakov
authors: V V
authors: VV
authors: Shubin
authors: B Ya
authors: BY
authors: Gurvits
mesh_terms: D000426:Alcohol Dehydrogenase / Q000737:chemistry / Q000187:drug effects; D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004044:Dietary Proteins / Q000378:metabolism*; D004229:Dithiothreitol / Q000737:chemistry / Q000494:pharmacology; D006454:Hemoglobins / Q000737:chemistry / Q000494:pharmacology; D006358:Hot Temperature; D007700:Kinetics; D007768:Lactalbumin / Q000737:chemistry / Q000187:drug effects; D008027:Light; D018847:Opioid Peptides / Q000378:metabolism* / Q000494:pharmacology*; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D011489:Protein Denaturation / Q000187:drug effects; D020673:Protein Renaturation / Q000187:drug effects*; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence
chemical_list: D004044:Dietary Proteins; D006454:Hemoglobins; D018847:Opioid Peptides; D010446:Peptide Fragments; C111722:exorphin C; C070563:hemorphin 6; C443992:rubiscolin 5; D007768:Lactalbumin; D000426:Alcohol Dehydrogenase; D012273:Ribulose-Bisphosphate Carboxylase; D004229:Dithiothreitol