Mixed DPPC/DPTAP Monolayers at the Air/Water Interface: Influence of Indolilo-3-acetic Acid and Selenate Ions on the Monolayer Morphology

Abstract

The interactions of mixed monolayers of two lipids, zwitterionic 1,2-dipalmitoyl-phosphatidylcholine (DPPC) and positively charged 1,2-dipalmitoyl-3-trimethylammonium-propane (DPTAP), with phytohormone indolilo-3-acetic acid (IAA) and selenate anions in the aqueous subphase were studied. For this purpose, isotherms of the surface pressure versus the mean molecular area were recorded. Domain formation was investigated by using Brewster angle microscopy (BAM). The method of grazing incidence X-ray diffraction (GIXD) was also applied for the characterization of the organization of lipid molecules in condensed monolayers. It was found that selenate ions contribute to monolayer condensation by neutralizing the positive net charge of mixed monolayers whereas IAA molecules penetrated the lipid monolayer, causing its expansion/fluidization. When both solutes were introduced into the subphase, a competition between them for interaction with the positively charged lipids in the monolayer was observed.

Lipophilic prodrug of paclitaxel: Interaction with a dimyristoylphosphatidylcholine monolayer

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Studies of Lipid Monolayers Prepared from Native and Model Plant Membranes in Their Interaction with Zearalenone and Its Mixture with Selenium Ions

“…On the basis of Langmuir monolayer technique, some steps in the mechanisms of physiological processes, especially those connected with the influence of hormones (Filek et al 2005; Gzyl et al 2004; Wnętrzak et al 2013), organic and non-organic ions (Gzyl-Malcher et al 2009, 2011; Rudolphi-Skórska et al 2014) have been interrelated. One of the important problems in plant physiology is to protect the cells against the mycotoxin accumulation (Diamond et al 2013).…”

Unraveling Tryptophan Modulated 2D DPPC Lattices: An Approach toward Stimuli Responsiveness of the Pulmonary Surfactant

“…Taking charge density, size, and molecular conformation into account, the favorable electrostatic interactions between the negatively charged macro-ion and the zwitterionic phosphocholine head-groups led to stabilization of the DPPC bilayer gel phase with increase in the main chain transition temperature. Gzyl-Malcher et al 30 discussed interactions of mixed monolayers of DPPC and DPTAP (dipalmitoyl trimethyl ammonium propane) with the phytohormone, indolilo-3-acetic acid, and selenate anions in the aqueous subphase. A pronounced condensing effect for the binary monolayers were related with reorientation of the P À ÀN + dipole of the DPPC headgroup from a parallel to a more vertical orientation.…”