Structure - membrane activity relationship in a family of peptide-based gemini amphiphiles: An insight from experimental and theoretical model systems.
A study of the interaction between five gemini amphiphilic valine-based pseudopeptides (GAPs) differing by the length of the central aliphatic spacer linking two amino acid subunits, and a model bacterial membrane lipid, 1,2-dimyristoyl-sn-glycero-3-phospho-rac-(1-glycerol) (DMPG), is here presented. Pure DMPG, pure GAPs and mixed GAPs/DMPG monolayers were formed at the air-water interface using Langmuir technique. The properties of the Langmuir films were investigated using surface pressure measurements, polarization modulation-infrared reflection-absorption spectroscopy, and Brewster angle microscopy. The atomic level information concerning the orientation of molecules in the monolayer and hydration of the polar headgroups was obtained from molecular dynamics simulations. It was demonstrated that the length of the central spacer in the GAPs structure is important for the properties of the mixed films; the disorganization of the membrane increases with the length of the spacer. The latter point is important for developing possible antimicrobial agents based on GAPs.
Department of Physical Chemistry and Electrochemistry, Faculty of Chemistry, Jagiellonian University, ul. R. Ingardena 3, 30-060 Krakow, Poland. Electronic address: bkorch@chemia.uj.edu.pl.
Beata
B
Korchowiec
Department of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, ul. R. Ingardena 3, 30-060 Krakow, Poland.
Marcelina
M
Gorczyca
Department of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University, ul. R. Ingardena 3, 30-060 Krakow, Poland.
Jacek
J
Korchowiec
Departamento de Química Inorgánica y Orgánica, Universidad Jaume I, Av. Sos Baynat, s/n, 12071 Castellon, Spain.
Jenifer
J
Rubio-Magnieto
Departamento de Química Inorgánica y Orgánica, Universidad Jaume I, Av. Sos Baynat, s/n, 12071 Castellon, Spain.
Ahmed H
AH
Lotfallah
Departamento de Química Inorgánica y Orgánica, Universidad Jaume I, Av. Sos Baynat, s/n, 12071 Castellon, Spain.
Santiago V
SV
Luis
Structure et Réactivité des Systèmes Moléculaires Complexes, BP 239, CNRS/Université de Lorraine, 54506 Vandoeuvre-lès-Nancy cedex, France. Electronic address: ewa.rogalska@univ-lorraine.fr.
Ewa
E
Rogalska
D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D010743:Phospholipids / Q000737:chemistry* / Q000378:metabolism; D013329:Structure-Activity Relationship; D013499:Surface Properties; D014633:Valine / Q000737:chemistry*
D010446:Peptide Fragments; D010743:Phospholipids; D014633:Valine
Biomembrane; Gemini surfactant; Molecular dynamics simulations; Peptide