TY - JOUR AU - Klacsová, Mária AU - Bóta, Attila AU - Westh, Peter AU - Funari, Sergio de Souza AU - Uhríková, Daniela AU - Balgavý, Pavol TI - Thermodynamic and structural study of DMPC–alkanol systems JO - Physical chemistry, chemical physics VL - 23 IS - 14 SN - 1463-9076 CY - Cambridge PB - RSC Publ. M1 - PUBDB-2022-00576 SP - 8598 - 8606 PY - 2021 N1 - Waiting for fulltext AB - The thermodynamic and structural behaviors of lamellar dimyristoylphosphatidylcholine-alkanol (abbreviation DMPC–CnOH, n = 8–18 is the even number of carbons in the alkyl chain) systems were studied by using DSC and SAXD/WAXD methods at a 0–0.8 CnOH : DMPC molar ratio range. Up to n ≤ 10 a significant biphasic effect depending on the main transition temperature t<sub>m</sub> on the CnOH concentration was observed. Two breakpoints were revealed: turning point (TP), corresponding to the minimum, and threshold concentration (c<sub>T</sub>), corresponding to the end of the biphasic tendency. These breakpoints were also observed in the alkanol concentration dependent change in the enthalpy of the main transition ΔH<sub>m</sub>. In the case of CnOHs with n > 10 we propose a marked shift of TP and c<sub>T</sub> to very low concentrations; consequently, only increase of tm is observed. A partial phase diagram was constructed for a pseudo-binary DMPC–C12OH system. We suggest a fluid–fluid immiscibility of the DMPC–C12OH system above c<sub>T</sub> with a consequent formation of domains with different C12OH contents. At a constant CnOH concentration, the effects of CnOHs on ΔH<sub>m</sub> and bilayer repeat distance were found to depend predominantly on the mismatch between CnOH and lipid chain lengths. Observed effects are suggested to be underlined by a counterbalancing effect of interchain van der Waals interactions and headgroup repulsion. LB - PUB:(DE-HGF)16 C6 - 33876021 UR - <Go to ISI:>//WOS:000633043800001 DO - DOI:10.1039/D0CP04991C UR - https://bib-pubdb1.desy.de/record/474186 ER -