A study on the interaction between 1-decyloxymethyl-3-carbamoylpyridinium salts and model membranes--the effect of counterions.
The interaction between 1-decyloxymethyl-3-carbamoylpyridinium salts (PS-X) and two types of vesicles (multilamellar vesicle and sonicated vesicle) was investigated. Vesicles were formed from two classes of phospholipids: 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphatidylethanolamine (DPPE). The PS-X salts used had nitrate, perchlorate, tetrafluoroborate and halides as counterions. Measurements were carried out using differential scanning calorimetry and 1H NMR. All studied compounds decreased the main phase transition temperatures of both DPPC and DPPE bilayers. All of them also decreased the transition enthalpy of DPPC bilayers, however they had a dual effect on the transition enthalpy of DPPE. Namely, at low concentrations the PS-X salts studied significantly increased the main transition enthalpy of DPPE (perchlorate and tetrafluoroborate the least among them) and decreased it at higher concentrations. We have suggested that surfactant rich and pure domains form on the DPPE bilayer in the presence of PS-ClO4, PS-BF4 and PS-NO3, whereas they form on DPPC bilayer only in the presence of PS-ClO4. Results are discussed in terms of counterion molecular geometry and the ability of amide group to form hydrogen bonds with lipids.
Rózycka-Roszak
Bozenna
B
Department of Physics and Biophysics, Agricultural University, Norwida 25, 50-375 Wrocław, Poland. boro@ozi.ar.wroc.pl
Przyczyna
Adriana
A
Pernak
Agnieszka
A
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D000838:Anions / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D008081:Liposomes / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008567:Membranes, Artificial; D008738:Methyl Ethers / Q000737:chemistry; D015394:Molecular Structure; D009536:Niacinamide / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry; D011726:Pyridinium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
D000838:Anions; D008081:Liposomes; D008567:Membranes, Artificial; D008738:Methyl Ethers; D010714:Phosphatidylethanolamines; D011726:Pyridinium Compounds; D013501:Surface-Active Agents; D009536:Niacinamide; D015060:1,2-Dipalmitoylphosphatidylcholine