title: The interaction of Mozobil™ with carboxylates.
abstract: Mozobil(™) (1,1'-[1,4-phenylenebis(methylene)]bis[1,4,8,11-tetraazacyclotetradecane], 1, also known as JM3100 and AMD 3100) is a specific antagonist of the chemokine coreceptor CXCR4 and favours the mobilisation from the bone marrow of stem cells, which can be used for autologous transplantation. It is believed that the interaction, of both hydrogen bonding and electrostatic nature, involves a partly protonated form of Mozobil(™), LHn(n+) and the COO(-) groups of Asp(171) and Asp(262) residues protruding from the walls of the pocket of the membrane protein CXCR4. We have investigated, through potentiometric titrations in 0.1 M NaNO3 at 25 °C, the interaction equilibria between 1 (L) and linear dicarboxylates A(2-). These studies have demonstrated that the main equilibrium takes place: LH5(5+) + A(2-)⇄ [LH5···A](3+), and that the most stable [LH5···A](3+) complex forms for A(2-) = diphenyl-4,4'-dicarboxylate, whose length matches that of LH5(5+). (1)H NMR titration experiments have shown that in the 7-10 pH interval, LH3(3+), LH2(2+) and LH(+) forms establish π-π interactions with diphenyl-4,4'-dicarboxylate, according to a topological arrangement which excludes the formation of H-bonds. It is finally suggested that, in the pocket of the CXCR4 membrane protein, Mozobil(™) operates as a pentammonium cation, which establishes with carboxylate groups of Asp(171) and Asp(262) strong interactions of hydrogen bonding and electrostatic nature.
authors.affiliation: Dipartimento di Chimica, Università di Pavia, viale Taramelli 12, 27100 Pavia, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Amendola
authors.forename: Greta
authors.initials: G
authors.lastname: Bergamaschi
authors.forename: Luigi
authors.initials: L
authors.lastname: Fabbrizzi
authors.forename: Maurizio
authors.initials: M
authors.lastname: Licchelli
authors.forename: Carlo
authors.initials: C
authors.lastname: Mangano
mesh_terms: D001596:Benzylamines; D002264:Carboxylic Acids / Q000737:chemistry* / Q000494:pharmacology; D000080027:Cyclams; D006571:Heterocyclic Compounds / Q000737:chemistry* / Q000494:pharmacology; D006801:Humans; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D019718:Receptors, CXCR4 / Q000037:antagonists & inhibitors / Q000737:chemistry; D055672:Static Electricity; D013329:Structure-Activity Relationship
chemical_list: D001596:Benzylamines; D002264:Carboxylic Acids; D000080027:Cyclams; D006571:Heterocyclic Compounds; D019718:Receptors, CXCR4; C088327:plerixafor