Novel benzanthrone aminoderivatives for membrane studies.

The potential of novel benzanthrone aminoderivatives to trace the changes in physicochemical properties of lipid bilayer has been evaluated. Binding of the dyes to the lipid bilayers composed of zwitterionic phospholipid phosphatidylcholine (PC) and its mixtures with anionic phospholipid cardiolipin (CL) and cholesterol (Chol) was followed by significant quantum yield increase with small blue shift of emission maximum. Analysis of partition coefficients of the dyes under study showed that all aminobenzanthrones possess high lipid-associating ability.

Cytochrome c-lipid interactions: new insights from resonance energy transfer.

Resonance energy transfer (RET) from anthrylvinyl-labeled phosphatidylcholine (AV-PC) or cardiolipin (AV-CL) to cytochrome c (cyt c) heme moiety was employed to assess the molecular-level details of protein interactions with lipid bilayers composed of PC with 2.5 (CL2.5), 5 (CL5), 10 (CL10), or 20 (CL20) mol % CL under conditions of varying ionic strength and lipid/protein molar ratio.

Morphological changes of supported lipid bilayers induced by lysozyme: planar domain formation vs. multilayer stacking.

Total internal reflection fluorescence microscopy (TIRFM) has been utilized to explore the effect of cationic protein lysozyme (Lz) on the morphology of solid-supported lipid bilayers (SLBs) comprised of zwitterionic lipid phosphatidylcholine (PC) and its mixture with anionic lipid cardiolipin (CL). Kinetic TIRFM imaging of different systems revealed subtle interplay between lipid lateral segregation accompanied by exchange of neutral and acidic lipids in the protein-lipid interaction zone, and the formation of lipid multilayer stacks. The switch between these states was shown to be controlled by CL content.

Nature of cationic poly(propylenimine) dendrimers in aqueous solutions as studied using versatile indicator dyes.

Aqueous solutions of four cationic poly(propylenimine) low-generation dendrimers of different architecture and hydrophobicity have been examined as media for acid-base reactions of indicator dyes. The cationic dendrimers in solution can be considered as oligomers of cationic polyelectrolytes, or surfactant-like species, able to form micelles through self-association or sometimes even as unimolecular micelles. The dendrimers influence the ionization constants, tautomeric equilibria, and absorption/emission/excitation spectra of indicator dyes.