The organization of lipids surrounding membrane proteins can influence their properties. We have used 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan) to study phase coexistence and phase interconversion in membrane model systems. The fluorescence properties of Laurdan provide a unique possibility to study lipid domains because of the different excitation and emission spectra of this probe in ...

Introduction: The lung surfactant dipalmitoylphosphatidylcholine (DPPC) leaks into the blood, settling on luminal aspect of blood vessels to create active hydrophobic spots. Nanobubbles are formed at these spots from dissolved gas. We hypothesized that when a large molecule in comes contact with nanobubble spots, its tertiary structure is disrupted. An exposed epitope may then prompt an autoimm...

A comparative study of the physical adsorption of RNAse A and RNAse Bacillus pumilis onto a negatively charged surface of mica, a hydrophobic surface of pyrolytic graphite and a surface of lipid layers of dipalmitoylphosphatidylcholine (DPPC) was performed by atomic force microscopy. It was found that microbial RNAse, unlike RNAse A, 1) is adsorbed onto the negatively charged surface of mica in...

A series of molecular dynamics computer simulations have been carried out on fully hydrated liquid crystalline dipalmitoyl phosphatidylcholine (DPPC) bilayers at constant surface areas corresponding to 59.3, 62.9, 65.5, or 68.1 Å2/lipid, the range of values suggested by different experiments in different laboratories. Simulated quantities are compared with those fromNMR (deuterium order paramet...

In agreement with recent reports, a commercial densimeter has yielded a gradual decrease in lipid molecular volume of DPPC multilamellar vesicle dispersions in the gel phase upon repeated thermal cycling between 10 °C and 50 °C. The considerable size of this decrease would have significant implications for the physical chemistry of biomembranes. In contrast, neutral buoyancy measurements perfor...

Biological symmetry breaking is a mechanism in biosystems that necessary for human survival, and depends on chemical physics concepts at both microscopic macroscopic scales. In this work, we present few mechanisms of the signaling phenomenon have been studied various tissues origin. We exhibit anatomical asymmetry structure membrane can produce flow extracellular fluid. Furthermore, misbalance ...

Pulmonary surfactant protein SP-C has been isolated from porcine lungs and treated with dansyl isothiocyanate in chloroform:methanol 2:1 (v/v) solutions,under conditions optimized to introduce a single dansyl group covalently attached to the N-terminalamine group of the protein without loss of its native thioesther-linked palmitic chains. The resulting derivative Dans-SP-C conserves the seconda...

The study compares the effect of the addition of two coumarins: 4-hydroxycoumarin (4-HC) and 7-hydroxycoumarin (umbelliferone; UMB) on dipalmitoylphosphatidylcholine (DPPC) membranes. The study was based on microcalorimetric and fluorescence measurements. The examinations have shown that 4-HC changes parameters of phase transition of DPPC membranes to a greater degree than UMB. It is associated...

Electron spin resonance (ESR) studies have been performed on spin-labeled model membranes aligned using the isopotential spin-dry ultracentrifugation (ISDU) method of Clark and Rothschild. This method relies on sedimentation of the membrane fragments onto a gravitational isopotential surface with simultaneous evaporation of the solvent in a vacuum ultracentrifuge to promote alignment. The degre...