We have studied the lipid binding of apoC-III with two types of mixed vesicles of DMPC (dimyristoyl phosphatidylcholine) and DPPC (dipalmitoyl phosphatidyl-choline). DMPC vesicles mixed with those of DPPC produce a macroscopic mixture in which the DMPC and DPPC vesicles remain intact. The circular dichroism and fluorescence spectra of apoC-III in the presence of this macroscopic mixture exhibit...

We have investigated the formation of supported bilayers by coadsorption of dipalmitoyl phosphatidylcholine (DPPC) with the nonionic surfactant beta-D-dodecyl maltoside. The adsorption of mixed phospholipid-surfactant micelles on hydrophilic silica surfaces at 25 degrees C was followed as a function of bulk concentration by neutron reflection. Using chain-deuterated d(25)-beta-D-dodecyl maltosi...

We have established a proteoliposome system as an osteoblast-derived matrix vesicle (MV) biomimetic to facilitate the study of the interplay of tissue-nonspecific alkaline phosphatase (TNAP) and NPP1 (nucleotide pyrophosphatase/phosphodiesterase-1) during catalysis of biomineralization substrates. First, we studied the incorporation of TNAP into liposomes of various lipid compositions (i.e. in ...

We have investigated by means of electron spin resonance (ESR) spectroscopy the influence of three inhalation anesthetics, i.e. halothane, chloroform and diethyl ether, on the interfacial and hydrophobic region as well of 38 mol% cholesterol containing DPPC unilamellar vesicles. The study has been carried out in the temperature range 25-45 degrees C. The variation of the order parameter, S, vs ...

In situ external reflection infrared spectroscopy at the air-water interface was used to study the influence on phospholipid structure of an endogenous mixture of the two hydrophobic surfactant proteins, SP-B and SP-C, which are thought to play pivotal roles in the adsorption and function of pulmonary surfactant. Mixtures studied were 1:1, 2:1, and 7:1 (mol:mol) DPPC-d(62):DPPG, and 7:1 DPPC-d(...

We identify energy contributions that drive PL chain ordering of DPPC and DLiPC lipids in cholesterol mixtures show not only contributes via direct interaction.

The mechanism of action of bovine milk lipoprotein lipase (LpL) was studied with a water-soluble substrate of p-nitrophenylbutyrate (PNPB). The calculated maximal velocity ( Vmm) and Michaelis constant (Km) values at 37 "C were 2.0 pmol of p-nitrophenol released/min/ mg of LpL and 0.52 mM, respectively. The addition of phospholipid vesicles enhanced the rate of PNPB hydrolysis by LpL. In the pr...

We studied the surface properties of monolayers composed of polyunsaturated conjugated ethylene glycol phospholipids (carotenoid lipids), compared the data with monolayers of dipalmitoylphosphatidylcholine (DPPC) to which carotenoids were added and evaluated the impact of the unsaturated glycol lipids on monolayers with the glycerolipid DPPC. The carotenoid based glycol lipids formed monolayers...

Monomolecular films of phospholipids in the liquid-expanded (LE) phase after supercompression to high surface pressures (pi), well above the equilibrium surface pressure (pi(e)) at which fluid films collapse from the interface to form a three-dimensional bulk phase, and in the tilted-condensed (TC) phase both replicate the resistance to collapse that is characteristic of alveolar films in the l...

Vitamin D2 (ergocalciferol) is a lipid soluble vitamin which does not occur naturally. It is obtained by irradiation of the provitamin ergosterol from yea@ which have ergosterol as their sterol component. It plays an important role in calcium and phosphorus metabolism, in immune function and cell differentiation [ 11 and recently it has been proposed as a membrane antioxidant [2]. Thm have been...