title: 2'-deoxy cyclic adenosine 5'-diphosphate ribose derivatives: importance of the 2'-hydroxyl motif for the antagonistic activity of 8-substituted cADPR derivatives.
abstract: The structural features needed for antagonism at the cyclic ADP-ribose (cADPR) receptor are unclear. Chemoenzymatic syntheses of novel 8-substituted 2'-deoxy-cADPR analogues, including 8-bromo-2'-deoxy-cADPR 7, 8-amino-2'-deoxy-cADPR 8, 8- O-methyl-2'-deoxy-cADPR 9, 8-phenyl-2'-deoxy-cADPR 10 and its ribose counterpart 8-phenyl-cADPR 5 are reported, including improved syntheses of established antagonists 8-amino-cADPR 2 and 8-bromo-cADPR 3. Aplysia californica ADP-ribosyl cyclase tolerates even the bulky 8-phenyl-nicotinamide adenine 5'-dinucleotide as a substrate. Structure-activity relationships of 8-substituted cADPR analogues in both Jurkat T-lymphocytes and sea urchin egg homogenate (SUH) were investigated. 2'-OH Deletion decreased antagonistic activity (at least for the 8-amino series), showing it to be an important motif. Some 8-substituted 2'-deoxy analogues showed agonist activity at higher concentrations, among which 8-bromo-2'-deoxy-cADPR 7 was, unexpectedly, a weak but almost full agonist in SUH and was membrane-permeant in whole eggs. Classical antagonists 2 and 3 also showed previously unobserved agonist activity at higher concentrations in both systems. The 2'-OH group, without effect on the Ca (2+)-mobilizing ability of cADPR itself, is an important motif for the antagonistic activities of 8-substituted cADPR analogues.
authors.affiliation: Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, UK.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Gerd K
authors.initials: GK
authors.lastname: Wagner
authors.forename: Karin
authors.initials: K
authors.lastname: Weber
authors.forename: Clive
authors.initials: C
authors.lastname: Garnham
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Morgan
authors.forename: Antony
authors.initials: A
authors.lastname: Galione
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Guse
authors.forename: Barry V L
authors.initials: BV
authors.lastname: Potter
mesh_terms: D036541:ADP-ribosyl Cyclase / Q000187:drug effects*; D000818:Animals; D001048:Aplysia; D002118:Calcium / Q000378:metabolism*; D036563:Cyclic ADP-Ribose / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D019169:Jurkat Cells; D047331:Lytechinus; D008968:Molecular Conformation; D010063:Ovum / Q000187:drug effects* / Q000378:metabolism; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism
chemical_list: D036563:Cyclic ADP-Ribose; D036541:ADP-ribosyl Cyclase; D002118:Calcium