title: Calcium and chlorpromazine binding to the EF-hand peptides of neuronal calcium sensor-1.
abstract: Neuronal calcium sensor-1, a protein of calcium sensor family, is known to have four structural EF-hands. We have synthesised peptides corresponding to all the four EF-hands and studied their conformation and calcium-binding. Our data confirm that the first putative site, a non-canonical one (EF1), does not bind calcium. We have investigated if this lack of binding is due to the presence of non-favoured residues (particularly at +x and -z co-ordinating positions) of the loop. We have mutated these residues and found that after modification the peptides bound calcium. However, these mutated peptides (EF1 and its functional mutants) do not show any Ca(2+) induced changes in far-UV CD. EF2, EF3, and EF4 peptides bind Ca(2+), EF3 being the strongest binder, followed by EF4. Our data of Ca(2+)-binding to individual EF peptides show that there are three active Ca(2+)-binding sites in NCS-1. We have also studied the binding of a neuroleptic drug, chlorpromazine, with the protein as well as with its EF-hands. CPZ binds myristoylated as well as non-myristoylated NCS-1 in Ca(2+)-dependent manner, with dynamic interaction to myristoylated protein. CPZ does not bind to EF1, but binds to functional EF-hand peptides and induces changes in far-UV CD. Our results suggest that NCS-1 could be a target of such antipsychotic and neuroleptic drugs.
authors.affiliation: Centre for Cellular and Molecular Biology (CCMB), Uppal Road, Hyderabad 500007, India.
authors.forename: Dasari
authors.initials: D
authors.lastname: Muralidhar
authors.forename: Maroor
authors.initials: M
authors.lastname: Kunjachen Jobby
authors.forename: Andreas
authors.initials: A
authors.lastname: Jeromin
authors.forename: John
authors.initials: J
authors.lastname: Roder
authors.forename: Fairwell
authors.initials: F
authors.lastname: Thomas
authors.forename: Yogendra
authors.initials: Y
authors.lastname: Sharma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002746:Chlorpromazine / Q000737:chemistry / Q000378:metabolism*; D020832:EF Hand Motifs; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D051580:Neuronal Calcium-Sensor Proteins; D009479:Neuropeptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017433:Protein Structure, Secondary; D016415:Sequence Alignment
chemical_list: D002135:Calcium-Binding Proteins; D051580:Neuronal Calcium-Sensor Proteins; D009479:Neuropeptides; C101464:frequenin calcium sensor proteins; D002118:Calcium; D002746:Chlorpromazine