1qiv
CALMODULIN COMPLEXED WITH N-(3,3,-DIPHENYLPROPYL)-N'-[1-R-(3,4-BIS-BUTOXYPHENYL)-ETHYL]-PROPYLENEDIAMINE (DPD), 1:2 COMPLEX
Structural highlights
FunctionCALM_BOVIN Calmodulin mediates the control of a large number of enzymes, ion channels and other proteins by Ca(2+). Among the enzymes to be stimulated by the calmodulin-Ca(2+) complex are a number of protein kinases and phosphatases. Together with CEP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis (By similarity). Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedAn arylalkylamine-type calmodulin antagonist, N-(3, 3-diphenylpropyl)-N'-[1-R-(3, 4-bis-butoxyphenyl)ethyl]-propylene-diamine (AAA) is presented and its complexes with calmodulin are characterized in solution and in the crystal. Near-UV circular dichroism spectra show that AAA binds to calmodulin with 2:1 stoichiometry in a Ca(2+)-dependent manner. The crystal structure with 2:1 stoichiometry is determined to 2.64 A resolution. The binding of AAA causes domain closure of calmodulin similar to that obtained with trifluoperazine. Solution and crystal data indicate that each of the two AAA molecules anchors in the hydrophobic pockets of calmodulin, overlapping with two trifluoperazine sites, i.e. at a hydrophobic pocket and an interdomain site. The two AAA molecules also interact with each other by hydrophobic forces. A competition enzymatic assay has revealed that AAA inhibits calmodulin-activated phosphodiesterase activity at two orders of magnitude lower concentration than trifluoperazine. The apparent dissociation constant of AAA to calmodulin is 18 nM, which is commensurable with that of target peptides. On the basis of the crystal structure, we propose that the high-affinity binding is mainly due to a favorable entropy term, as the AAA molecule makes multiple contacts in its complex with calmodulin. A new potent calmodulin antagonist with arylalkylamine structure: crystallographic, spectroscopic and functional studies.,Harmat V, Bocskei Z, Naray-Szabo G, Bata I, Csutor AS, Hermecz I, Aranyi P, Szabo B, Liliom K, Vertessy BG, Ovadi J J Mol Biol. 2000 Mar 31;297(3):747-55. PMID:10731425[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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