Origin of lipid tilt in flat monolayers and bilayers.

This paper continues the series of our works devoted to the liquid-gel phase transition in lipid membranes. Previously we described a variation of area per lipid, membrane thickness, and diffusion coefficient at the temperature-driven liquid-gel phase transition in bilayers. Here we expand the application of our analytic model approach to include a description of the lipid tilt and also extend the investigation to include Langmuir and self-assembled monolayers.

Lipid lateral self-diffusion drop at liquid-gel phase transition.

A drop of lipid lateral self-diffusion coefficient at the liquid-gel phase transition in lipid membranes is calculated. So far this drop was missing theoretical description. Our microscopic model captures so-called subdiffusion regime, which takes place on 1 ps-100 ns timescale and reveals a jump of self-diffusion coefficient.

Analytical calculation of the lipid bilayer bending modulus.

Bending and Gaussian moduli of a homogenious single-component lipid bilayer are calculated analytically using microscopic model of the lipid hydrocarbon chains. The approach allows for thermodynamic averaging over different chains conformations. Each chain is modeled as a flexible string with finite bending rigidity and an incompressible cross-section area.

Analytical approach to thermodynamics of bolalipid membranes.

In this work we derive analytically various thermodynamic properties of bolalipid membranes using microscopic model (elastic strings) and path-integral technique. Among calculated characteristics are lateral pressure profile (with and without hairpin bolalipids), chain orientational order parameter, pressure-area isotherms, coefficient of thermal area expansion, compressibility modulus, and area per bolalipid chain as a function of temperature. Results are compared with our previous ones for a monopolar lipid bilayer and with results of other relevant studies.

Pi-extended dipyrrins capable of highly fluorogenic complexation with metal ions.

The synthesis and properties of a new family of pi-extended dipyrrins capable of forming brightly fluorescent complexes with metal ions are reported. The metal complexes possess tunable spectral bands and exhibit different emission properties depending on the mode of metal coordination.

Analytical derivation of thermodynamic characteristics of lipid bilayer from a flexible string model.

We introduce a flexible string model of the hydrocarbon chain and derive an analytical expression for the lateral pressure profile across the hydrophobic core of the membrane. The pressure profile influences the functioning of the embedded proteins and is difficult to measure experimentally. In our model the hydrocarbon chain is represented as a flexible string of finite thickness with a given bending rigidity.