Specificity of Ca2+ and Mg2+ binding to phosphatidylserine vesicles and resultant phase changes of bilayer membrane structure.
Differences in the interaction of Ca2+ and Mg2+ with phosphatidylserine vesicles were revealed by binding studies, differential scanning calorimetry and X-ray diffraction. The two cations produced structurally different complexes with phosphatidylserine as evidenced by phase transition characteristics, lamellar spacings, and hydrocarbon packing. Ca2+ effectively completes with Mg2+ for phosphatidylserine binding sites. Analysis of the binding data showed that Ca2+ had a ten-fold greater intrinsic binding constant for phosphatidylserine.
D001665:Binding Sites; D002118:Calcium; D055598:Chemical Phenomena; D002621:Chemistry; D008081:Liposomes; D008274:Magnesium; D009994:Osmolar Concentration; D010718:Phosphatidylserines; D013499:Surface Properties
D008081:Liposomes; D010718:Phosphatidylserines; D008274:Magnesium; D002118:Calcium