title: Membrane structure and interactions of peptide hormones with model lipid bilayers.
abstract: In this work, the behavior of the neurohypophyseal hormones and their selected analogs was studied in the presence of membrane models in an attempt to correlate their activities with a distinct behavior at a level of peptide-lipid interactions. The influence of the peptides studied on the lipid acyl chain order was determined using FTIR spectroscopy. Conformational changes in the peptides upon binding to liposomes were examined using CD spectra. Attempts were also made to determine the binding parameters of the peptides to lipids using isothermal titration calorimetry (ITC). The results show unambiguously that the neurohyphophyseal hormone-like peptides interact with lipids, being a model of a eukaryotic cell membrane. Moreover, hydrophobic interactions between the peptides and liposomes are likely to determine the overall conformation of the peptide, especially below the temperature of the main phase transition (T(m)). Thus, the bulky and hydrophobic nature of the residues incorporated into the N-terminal part of neurohyphophyseal hormones is an important factor for both restriction of peptide mobility and the interaction of the analog with biomembrane. In turn, above T(m), the electrostatic interactions become also relevant for the conformation of the acyclic tail of the AVP-like peptides.
authors: Faculty of Chemistry, University of Gdańsk, Poland. milka@chem.univ.gda.pl
authors: Emilia
authors: E
authors: Sikorska
authors: Emilia
authors: E
authors: Iłowska
authors: Dariusz
authors: D
authors: Wyrzykowski
authors: Anna
authors: A
authors: Kwiatkowska
mesh_terms: D002152:Calorimetry, Differential Scanning; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D021961:Cell Membrane Structures; D057927:Hydrophobic and Hydrophilic Interactions; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism*; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D036361:Peptide Hormones / Q000737:chemistry / Q000378:metabolism*; D010909:Pituitary Hormones, Posterior / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary
chemical_list: D008051:Lipid Bilayers; D008081:Liposomes; D036361:Peptide Hormones; D010909:Pituitary Hormones, Posterior