Is spectrin a calmodulin-binding protein?

The binding of calmodulin to spectrin from human erythrocytes has been studied by affinity chromatography on sepharose-calmodulin column. The alpha and beta spectrin chains, dissociated in 6-7 M urea, both bound to the sepharose-calmodulin column, but with different affinities. Both chains were eluted together by EGTA. Binding sites for calmodulin are, therefore, present in both alpha and beta chains. However, intact purified spectrin dimers did not bind to the sepharose-calmodulin column, which renders a physiological role of calmodulin-binding to spectrin rather unlikely.