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Free keywords:
calcium binding; bioelectrochemistry; Ca2+-sensitive electrodes, spectrin.
Abstract:
Spectrin, a protein located at the inner surface of the red blood cell membrane, was isolated and investigated with respect to the binding of calcium. Aggregation phenomena were found to be due to the age of spectrin. The electrostatic interaction factor using the Linderstro̸m‐Lang method was found to be very weak, W < 0.01. Calcium binding occurred at 780 sites as indicated by Scatchard plots based on titration curves using a calcium‐sensitive electrode. Titration curves showed in addition the occurrence of conformational changes. The presence of calcium caused the formation of filaments seen in the electron micrographs. The results of binding studies of calcium to spectrin may give information about the influence of calcium on the change of shape of red cell membranes in which spectrin is suggested to be involved.