title: Dual-site binding of bivalent 4-aminopyridine- and 4-aminoquinoline-based AChE inhibitors: contribution of the hydrophobic alkylene tether to monomer and dimer affinities.
abstract: Three series of 4-aminopyridine-and 4-aminoquinoline based symmetrical bivalent acetylcholinesterase (AChE) inhibitors were prepared and compared to previously synthesized dimers of 9-amino-1,2,3,4-tetrahydroacridine (tacrine). In each case significant, tether length-dependent increases in AChE inhibition potency and selectivity (up to 3000-fold) were observed relative to the corresponding monomer, indicating dual-site binding of these inhibitors to AChE. Assay of the corresponding alkylated monomers revealed that the alkylene tether played at least two complementary roles in the dimer series. In addition to reducing the entropy loss that occurs on binding both monomeric units of the dimer, the alkylene tether can also significantly improve potency through hydrophobic effects.
authors.affiliation: Department of Biochemistry, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon.
authors.forename: Y F
authors.initials: YF
authors.lastname: Han
authors.forename: C P
authors.initials: CP
authors.lastname: Li
authors.forename: E
authors.initials: E
authors.lastname: Chow
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: Y P
authors.initials: YP
authors.lastname: Pang
authors.forename: P R
authors.initials: PR
authors.lastname: Carlier
mesh_terms: D015761:4-Aminopyridine / Q000737:chemistry* / Q000494:pharmacology; D000110:Acetylcholinesterase / Q000187:drug effects / Q000378:metabolism*; D000634:Aminoquinolines / Q000737:chemistry* / Q000494:pharmacology; D001665:Binding Sites; D002800:Cholinesterase Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology; D019281:Dimerization; D015195:Drug Design; D013329:Structure-Activity Relationship
chemical_list: D000634:Aminoquinolines; D002800:Cholinesterase Inhibitors; D015761:4-Aminopyridine; D000110:Acetylcholinesterase; C001920:4-aminoquinoline