title: [The influence of dipole modifiers on the channel-forming activity of amyloid and amyloid-like peptides in lipid bilayers].
abstract: We have studied the steady-state transmembrane current induced by amyloid and amyloid-like peptides in lipid bilayers in the presence of dipole modifiers. It has been shown that the addition of dipole modifier, phloretin, to the membrane bathing solutions leads to an increase in the multichannel activity of amyloid beta-peptide fragment 25-35, [Gly35]-amyloid beta-peptide fragment 25--35, prion protein fragment 106-126 and amyloid-like peptides myr-BASP1 (1--13), myr-BASP1(1--19) and GAP-43(1--40). We have found that the effect of phloretin is not the result of dipole potential changes due to adsorption of this modifier on the membrane. Using the various fragments of amyloid beta-peptide, presenilin, prion protein and neuronal proteins BASP1 and GAP-43 allowes to conclude that the steady-state peptide-induced transmembrane current in the case of addition of phloretin is due to the electrostatic interaction between the positively charged channel-forming agents and negatively charged dipole modifier. The results obtained by electron microscopy have demonstrated that this interaction increases degree of peptide oligomerization.
authors.forename: S S
authors.initials: SS
authors.lastname: Efimova
authors.forename: V V
authors.initials: VV
authors.lastname: Zakharov
authors.forename: O S
authors.initials: OS
authors.lastname: Ostroumova
mesh_terms: D016229:Amyloid beta-Peptides / Q000187:drug effects / Q000648:ultrastructure*; D019922:GAP-43 Protein / Q000187:drug effects / Q000648:ultrastructure*; D006801:Humans; D008051:Lipid Bilayers / Q000138:chemical synthesis / Q000378:metabolism; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000187:drug effects / Q000648:ultrastructure*; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000187:drug effects / Q000648:ultrastructure*; D010446:Peptide Fragments / Q000187:drug effects / Q000648:ultrastructure*; D010693:Phloretin / Q000494:pharmacology; D011328:Prions / Q000187:drug effects / Q000648:ultrastructure*; D012097:Repressor Proteins / Q000187:drug effects / Q000648:ultrastructure*; D055672:Static Electricity
chemical_list: D016229:Amyloid beta-Peptides; C104089:BASP1 protein, human; D019922:GAP-43 Protein; D008051:Lipid Bilayers; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D011328:Prions; D012097:Repressor Proteins; C074636:amyloid beta-protein (25-35); C082632:prion protein (106-126); D010693:Phloretin