title: Cu(2+)-heparin interaction studied by polarimetry.
abstract: Plots analogous to isothermal binding curves were derived from polarimetric studies of solutions of Na(+)-heparin to which Cu2+ was added. The shape of the plots suggests that discrete Cu(2+)-heparin complexes may form, the nature and stoichiometry of which depend upon the conditions under which the interaction occurs. Initially, complexes were formed with a stoichiometry of about 1 Cu2+ ion per heparin tetrasaccharide unit. Under these conditions, the complex may exist as a colloid-like phase that is not subject to simple solution equilibrium processes, and that is maintained by forces in addition to electrostatic ones. Further addition of Cu2+ resulted in the formation of a different complex with a stoichiometry of about 1 Cu2+ ion per disaccharide unit.
authors.affiliation: Department of Molecular and Cell Biology, University of Aberdeen, Marischal College, Scotland, U.K.
authors.forename: D
authors.initials: D
authors.lastname: Grant
authors.forename: W F
authors.initials: WF
authors.lastname: Long
authors.forename: C F
authors.initials: CF
authors.lastname: Moffat
authors.forename: F B
authors.initials: FB
authors.lastname: Williamson
mesh_terms: D002412:Cations / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D006493:Heparin / Q000737:chemistry*; D007700:Kinetics; D009904:Optical Rotation; D011048:Polarography; D013816:Thermodynamics
chemical_list: D002412:Cations; D003300:Copper; D006493:Heparin