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We have investigated the effect of a series of hydrophobic polypeptides (WALP peptides) on the mean hydrophobic thickness of (chain-perdeuterated) phosphatidylcholines (PCs) with different acyl chain length, using 2H NMR and ESR techniques. The WALP peptides are uncharged and consist of a sequence with variable length of alternating leucine and alanine,(More)
Bone regeneration is a common biological process occurring, for example, during fracture healing or osseo-integration of prostheses. Computer simulation of bone regeneration is difficult to carry out because it is a complex sequence of cell-mediated processes regulated by mechanobiological stimuli. An algorithm to predict the time-course of intramembranous(More)
  • D Marsh
  • 2001
The isotropic (14)N-hyperfine coupling constant, a(o)(N), of nitroxide spin labels is dependent on the local environmental polarity. The dependence of a(o)(N) in fluid phospholipid bilayer membranes on the C-atom position, n, of the nitroxide in the sn-2 chain of a spin-labeled diacyl glycerophospholipid therefore determines the transmembrane polarity(More)
Implications of the data on lipid-protein interactions involving integral proteins that are obtained from EPR spectroscopy with spin-labelled lipids in membranes are reviewed. The lipid stoichiometry, selectivity and exchange dynamics at the lipid-protein interface can be determined, in addition to information on the configuration and rotational dynamics of(More)
The intrinsic or spontaneous radius of curvature, R(o), of lipid monolayer assemblies is expressed in terms of a lipid molecular packing parameter, V/AI, for various geometries. It is shown that the equivalent lipid length, 1, in inverted hexagonal (HII) phases, defined by a cylindrical shell of equal total lipid volume, yields an expression for R o(More)
Spin-label electron spin resonance (ESR) spectroscopy and auxiliary optical density measurements are used to study lipid dispersions of N-poly(ethylene glycol)-dipalmitoyl phosphatidylethanolamine (PEG:5000-DPPE) mixed with dipalmitoyl phosphatidylcholine (DPPC). PEG:5000-DPPE bears a large hydrophilic polymer headgroup (with approximately 114 oxyethylene(More)
The critical micelle concentrations (cmc's) of a variety of spin-labeled phospholipids, 1-acyl-2-[4-(4,4-dimethyloxazolidine-N-oxyl)valeryl]-sn-glycero-3-pho sph o derivatives, have been determined by electron spin resonance (ESR) spectroscopy. The narrow, three-line ESR spectra of the rapidly tumbling monomers are clearly distinguished from the spin-spin(More)
Phospholipids when dispersed in excess water generally form vesicular membrane structures. Cryo-transmission and freeze-fracture electron microscopy are combined here with calorimetry and viscometry to demonstrate the reversible conversion of phosphatidylglycerol aqueous vesicle suspensions to a three-dimensional structure that consists of extended bilayer(More)
Bending elasticity is an important property of lipid vesicles, non-lamellar lipid phases and biological membranes. Experimental values of the mean curvature moduli, k(c), of lipid bilayers and of the monolayer leaflets of inverted hexagonal (H(II)) phases of lipids are tabulated here for easy reference. Experimental estimates of the Gaussian curvature(More)