We have purified the brain-specific S100b by affinity-based adsorption chromatography on phenothiazine-Sepharose conjugates and studied the interaction of this and other calcium-modulated proteins with the immobilized antipsychotic drug. Bovine brain calmodulin, rabbit skeletal muscle troponin C, and bovine brain S100b bind to phenothiazine-Sepharose in a calcium-dependent manner. These three proteins competitively inhibit the calcium-dependent binding of 125I-labeled chicken gizzard calmodulin to the immobilized drug. However, carp parvalbumin and chicken intestinal vitamin D-dependent calcium binding protein do not inhibit the phenothiazine-calmodulin interaction. These results suggest that the known amino acid sequence homology among calmodulin, troponin C, and S100b may be reflected in a similar functional domain present in these proteins but absent in parvalbumin and vitamin D-dependent protein.
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Issue number||11 II|
|State||Published - 1981|
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