Mutations in ABC1 in Tangier disease and familial high-density lipoprotein deficiency

Genes have a major role in the control of high-density lipoprotein (HDL) cholesterol (HDL-C) levels. Here we have identified two Tangier disease (TD) families, confirmed 9q31 linkage and refined the disease locus to a limited genomic region containing the gene encoding the ATP-binding cassette transporter (ABC1). Familial HDL deficiency (FHA) is a more frequent cause of low HDL levels. On the basis of independent linkage and meiotic recombinants, we localized the FHA locus to the same genomic region as the TD locus. Mutations in ABC1 were detected in both TD and FHA, indicating that TD and FHA are allelic. This indicates that the protein encoded by ABC1 is a key gatekeeper influencing intracellular cholesterol transport, hence we have named it cholesterol efflux regulatory protein (CERP

Tri-, Tetra-, and Hexanuclear Copper(II) Phosphonates Containing N-Donor Chelating Ligands: Synthesis, Structure, Magnetic Properties, and Nuclease Activity

Reaction of Cu(ClO4)2 3 6H2O with cyclopentyl phosphonic acid and 2,20-bipyridine (bpy) in presence of triethylamine afforded a trinuclear compound [Cu3(C5H9PO3)2(bpy)3(MeOH)(H2O)](ClO4)2 (2). The latter dimerizes to a hexanuclear derivative [Cu6(C5H9PO3)4(bpy)6(MeOH)4](ClO4)4 (1) under prolonged reaction conditions. Reaction of CuCl2 with cyclopentyl phosphonic acid and 2,20-bipyridylamine (bpya) affords a tetranuclear derivative [Cu4(C5H9PO3)2( μ-Cl)2(bpya)4](Cl)2, (MeOH)2 (3). Reaction of the latter with NaClO4 also affords a trinuclear compound [Cu3(C5H9PO3)2( μ-Cl)(bpya)3(H2O)](ClO4) (4). Double and single-bridged hexanuclear species, [{Cu3(C5H9PO3)2(bpy)3(bpp)}(MeOH)2(H2O)(CH2Cl2)(ClO4)2]2 (5), [{Cu3(i- PrPO3)2(bpy)3(4.40-bpy)(H2O)}(H2O)2(ClO4)2]2 (6), [{Cu3(C5H9PO3)2(bpya)3(4.40-bpy)(H2O)}(MeOH)(H2O)(ClO4)2]2 (7), and [Cu6(t-BuPO3)4(phen)6(4,40-bpy)(MeOH)4](CH2Cl2)(H2O)(ClO4)4 (8) (phen = 1,10-phenanthroline) were obtained by the reaction of an in situ generated trinuclear complex with appropriate bridging ligands 4,40-bipyridine (4,40-bpy) or 1,3-bis(4- pyridyl)propane (bpp). ESI-MS studies of these complexes reveal that 2-4 retain their structures in solution. Molecular structures of 2-8 were determined by X-ray crystallography. All the compounds reveal a capping coordination mode by tridentate phosphonate [RPO3]2- ligands. Detailed magnetic studies on 2 and 4-8 reveal intramolecular antiferromagnetic interactions between Cu(II) S = 1/2 spins. 2 and 4 are excellent artificial nucleases and can convert supercoiled plasmid DNA (pBR322) into its nicked form without the aid of an external oxidant