The crystal structure of calmodulin (CaM) bound to trifluoperazine (TFP) has been determined and refined to a resolution of 2.45 A. Only one TFP is bound to CaM, but that is sufficient to cause distortion of the central alpha-helix and juxtaposition of the N- and C-terminal domains similar to that seen in CaM-polypeptide complexes. The drug makes extensive contacts with residues in the C-terminal domain of CaM but only a few contacts with one residue in the N-terminal domain. The structure suggests that substrate binding to the C-terminal domain is sufficient to cause the conformational changes in calmodulin that lead to activation of its targets.
Drug binding by calmodulin: crystal structure of a calmodulin-trifluoperazine complex.,Cook WJ, Walter LJ, Walter MR Biochemistry. 1994 Dec 27;33(51):15259-65. PMID:7803388
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.