title: The chemosensitizing agent lubeluzole binds calmodulin and inhibits Ca(2+)/calmodulin-dependent kinase II.
abstract: An affinity capillary electrophoresis (ACE) method to estimate apparent dissociation constants between bovine brain calmodulin (CaM) and non-peptidic ligands was developed. The method was validated reproducing the dissociation constants of a number of well-known CaM ligands. In particular, the potent antagonist 125-C9 was ad hoc synthesized through an improved synthetic procedure. The ACE method was successfully applied to verify CaM affinity for lubeluzole, a well-known neuroprotective agent recently proved useful to potentiate the activity of anti-cancer drugs. Lubeluzole was slightly less potent than 125-C9 (Kd = 2.9 ± 0.7 and 0.47 ± 0.06 μM, respectively) and displayed Ca(2+)/calmodulin-dependent kinase II (CaMKII) inhibition (IC50 = 40 ± 1 μM). Possible binding modes of lubeluzole to CaM were explored by docking studies based on the X-ray crystal structures of several trifluoperazine-CaM complexes. An estimated dissociation constant in good agreement with the experimental one was found and the main aminoacidic residues and interactions contributing to complex formation were highlighted. The possibility that interference with Ca(2+) pathways may contribute to the previously observed chemosensitizing effects of lubeluzole on human ovarian adenocarcinoma and lung carcinoma cells are discussed.
authors.affiliation: Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari 'Aldo Moro', via E. Orabona 4, 70126 Bari, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bruno
authors.affiliation: Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari 'Aldo Moro', via E. Orabona 4, 70126 Bari, Italy. Electronic address: mariamaddalena.cavalluzzi@uniba.it.
authors.forename: Maria Maddalena
authors.initials: MM
authors.lastname: Cavalluzzi
authors.affiliation: Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università Federico II, 80131 Napoli, Italy.
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Rusciano
authors.affiliation: Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari 'Aldo Moro', via E. Orabona 4, 70126 Bari, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Lovece
authors.affiliation: Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari 'Aldo Moro', via E. Orabona 4, 70126 Bari, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Carrieri
authors.affiliation: Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari 'Aldo Moro', via E. Orabona 4, 70126 Bari, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Pracella
authors.affiliation: Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università degli Studi di Bari' Aldo Moro', via E. Orabona 4, 70126 Bari, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Giannuzzi
authors.affiliation: Dipartimento dell'Emergenza e dei Trapianti di Organi, Policlinico - P.zza Giulio Cesare, 70124 Bari, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Polimeno
authors.affiliation: IRCCS Azienda Ospedaliera Universitaria San Martino - IST Istituto Nazionale per la Ricerca sul Cancro (IRCCS SMIST), U.O.C. Terapia Immunologia, L.go R. Benzi, 10, 16132 Genova, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Viale
authors.affiliation: Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università Federico II, 80131 Napoli, Italy.
authors.forename: Maddalena
authors.initials: M
authors.lastname: Illario
authors.affiliation: Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari 'Aldo Moro', via E. Orabona 4, 70126 Bari, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Franchini
authors.affiliation: Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari 'Aldo Moro', via E. Orabona 4, 70126 Bari, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Lentini
mesh_terms: D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism*; D002417:Cattle; D006801:Humans; D062105:Molecular Docking Simulation; D010880:Piperidines / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D011487:Protein Conformation; D047428:Protein Kinase Inhibitors / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*; D013844:Thiazoles / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D002147:Calmodulin; D010880:Piperidines; D047428:Protein Kinase Inhibitors; D013844:Thiazoles; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; C097722:lubeluzole
keywords: Affinity capillary electrophoresis; Anti-cancer activity; Calmodulin; Docking; Human carcinoma cells; Lubeluzole; Voltage-gated sodium channels