A spontaneous membrane assembly process has been postulated to account for the rapid perigranular membrane enlargement which occurs during mast cell secretory granule activation. This process requires the presence of a phospholipid store in the quiescent granule. By using purified granules with intact membranes we have determined the total phospholipid content of the average quiescent granule. ...

Phospholipid molecules are composed of multipolar headgroup and two electrically neutral hydrocarbon tails. The inverted hexagonal phase (HII ) belongs to the biologically most significant non-lamellar phospholipid phases in biomembranes. Hence the geometric properties and conditions of transition to the HII phase are nowadays widely studied. In our derivation of the free energy of lipid monola...

The indispensability of phospholipid and ubiquinone (Q) in mitochondrial electron transfer was studied by depleting phospholipid and Q in succinate-cytochrome c reductase and then replenishing the depleted enzyme. More than 90% of phospholipid and Q was removed by repeated ammonium sulfate-cholate fractionation. The depleted succinate-cytochrome c reductase showed no enzymatic activity for succ...

The rates of specific catalytic events in the mitochondrial inner membrane were determined after enriching the membrane bilayer with exogenous phospholipid. Inner membranes were fused with soybean phospholipid, then separated into four buoyant-distinct fractions by sucrose density centrifugation. Analysis revealed a progressively increasing phospholipid to protein ratio from the least buoyant (...

Annexin V is a 36-kDa protein which, it has been suggested, is a factor in protecting the vascular endothelium from attack by antibodies to other phospholipid-binding proteins. Competition between annexin V and beta2-glycoprotein I (beta2GPI) for phospholipid surfaces is complicated by empirical observations regarding alterations in binding to anionic phospholipid, primarily phosphatidylserine....

The composition of the phospholipids and of the total phospholipid fatty acids was determined in the plasma of 10 normal subjects. In addition the fatty acid composition of the plasma phosphatidyl ethanolamine, phosphatidyl serine, lecithin, sphingomyelin, and lysolecithin of 6 of the subjects was measured. A wide array of fatty acids was found in the plasma total phospholipid similar to that f...

Several unusual complexes of ytterbium(ii) stabilised by coordination to mixed O4X2-donor macrocyclic ligands (X = O, NH, S or Se) are described. Distorted 8-coordination is evident from the crystal structure of the neutral [YbI2([18]aneO4Se2)], forming the first reported example of Yb(ii)-selenoether coordination.