Binding of Calcium and Magnesium Ions to Human Erythrocyte Membranes

概要

論文の詳細を見る
Binding of calcium and magnesium ions to human erythrocyte membrane was investigated by determination of these cations by means of atomic absorption spectrophotometry. Roles of the membrane components in the binding were also studied. Mean Ca and Mg contents of the erythrocyte stroma are 22 and 40 n moles, respectively, per stroma equivalent to 1 ml of the packed erythrocytes. About 60 and 40% of the membrane Ca are associated respectively with the outer and inner surface of the membrane, whereas about 15% of the membrane Mg are burried in the intra-membrane region and the remaining 85% are loosely adsorbed onto the membrane surfaces which are removable by simple saline washes. The erythrocyte stroma can bind large amounts of Ca and Mg additionally from the surrounding medium. These "exogenous" divalent cations are, however, easily removed by simple saline washes and the binding seems to be non-specific with respect to the ion species. At least three different kinds of sites each are concerned in the binding of Ca or Mg to the membrane. Membrane lipids, in addition to membrane proteins, are thought to play important roles in the association of the firmly-bound Ca (Ca originally present) in the membrane, but not so much in the additional binding of Ca from the medium.
社団法人日本薬学会の論文
1974-02-25