title: Comparative study of the interaction of synthetic methionine-enkephalin and its amidated derivate with monolayers of zwitterionic and negatively charged phospholipids.
abstract: Using Langmuir's monolayer technique, the surface behavior and the interaction of the synthetic neuropeptide methionine-enkephalin (Met-enk) and its amidated derivate (Met-enk-NH(2)) with monolayers of the zwitterionic dimyristoylphosphatidylcholine (DMPC) and the negatively charged dimyristoylphosphatidylglycerol (DMPG) were studied. The surface tension (γ, mN/m) of DMPG and DMPC monolayers as a function of time (after injection of the peptide under the interface) was detected. The decrease in γ values showed that there was a strong penetration effect of both types of Met-enk molecules into the monolayers, being significantly stronger for the amidated derivate, Met-enk-NH(2). We suggest that the interaction between the neuropeptides and DMPC was predominantly determined by peptides amphiphilicity, while the electrostatic forces play significant role for the insertion of the cationic Met-enk-NH(2) in DMPG monolayers, especially at high packing densities. Our results demonstrate the potential of lipid monolayers formed in Langmuir's trough to be successfully used as an elegant and simple membrane models to study lipid-peptide interactions at the air/water interface.
authors.affiliation: Faculty of Medicine, St. Kliment Ohridski University of Sofia, 1 Kozyak Str., 1407, Sofia, Bulgaria. assja_t@yahoo.com
authors.forename: Asya
authors.initials: A
authors.lastname: Tsanova
authors.forename: A
authors.initials: A
authors.lastname: Jordanova
authors.forename: G As
authors.initials: GA
authors.lastname: Georgiev
authors.forename: T
authors.initials: T
authors.lastname: Pajpanova
authors.forename: E
authors.initials: E
authors.lastname: Golovinsky
authors.forename: Z
authors.initials: Z
authors.lastname: Lalchev
mesh_terms: D000577:Amides / Q000138:chemical synthesis / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D004745:Enkephalins / Q000138:chemical synthesis / Q000737:chemistry*; D008567:Membranes, Artificial; D008715:Methionine / Q000138:chemical synthesis / Q000737:chemistry*; D010715:Phosphatidylglycerols / Q000737:chemistry*; D013500:Surface Tension
chemical_list: D000577:Amides; D004745:Enkephalins; D008567:Membranes, Artificial; D010715:Phosphatidylglycerols; D008715:Methionine; C002773:dimyristoylphosphatidylglycerol; D004134:Dimyristoylphosphatidylcholine