TY - JOUR
T1 - Structure-activity relationships for the interactions of 2′- and 3′-(O)-(N-methyl)anthraniloyl-substituted purine and pyrimidine nucleotides with mammalian adenylyl cyclases
AU - Pinto, Cibele
AU - Lushington, Gerald H.
AU - Richter, Mark
AU - Gille, Andreas
AU - Geduhn, Jens
AU - König, Burkhard
AU - Mou, Tung Chung
AU - Sprang, Stephen R.
AU - Seifert, Roland
N1 - Funding Information:
This work was supported by Deutsche Forschungsgemeinschaft research grant Se 529/5-2 to R.S. and NIH grant 2R56 DK46371-14 to S.R.S. Thanks are due to the reviewers for their helpful critique.
PY - 2011/8/15
Y1 - 2011/8/15
N2 - Membranous adenylyl cyclases (ACs) play a key role in signal transduction and are promising drug targets. In previous studies we showed that 2′,3′-(O)-(N-methylanthraniloyl) (MANT)-substituted nucleotides are potent AC inhibitors. The aim of this study was to provide systematic structure-activity relationships for 21 (M)ANT-substituted nucleotides at the purified catalytic AC subunit heterodimer VC1:IIC2, the VC1:VC1 homodimer and recombinant ACs 1, 2 and 5. (M)ANT-nucleotides inhibited fully activated VC1:IIC2 in the order of affinity for bases hypoxanthine > uracil > cytosine > adenine ∼ guanine xanthine. Omission of a hydroxyl group at the 2′ or 3′-position reduced inhibitor potency as did introduction of a γ-thiophosphate group or omission of the γ-phosphate group. Substitution of the MANT-group by an ANT-group had little effect on affinity. Although all nucleotides bound to VC1:IIC2 similarly according to the tripartite pharmacophore model with a site for the base, the ribose, and the phosphate chain, nucleotides exhibited subtle differences in their binding modes as revealed by fluorescence spectroscopy and molecular modelling. MANT-nucleotides also differentially interacted with the VC1:VC1 homodimer as assessed by fluorescence spectroscopy and modelling. Similar structure-activity relationships as for VC1:IIC2 were obtained for recombinant ACs 1, 2 and 5, with AC2 being the least sensitive AC isoform in terms of inhibition. Overall, ACs possess a broad base-specificity with no preference for the "cognate" base adenine as verified by enzyme inhibition, fluorescence spectroscopy and molecular modelling. These properties of ACs are indicative for ligand-specific conformational landscapes that extend to the VC1:VC1 homodimer and should facilitate development of non-nucleotide inhibitors.
AB - Membranous adenylyl cyclases (ACs) play a key role in signal transduction and are promising drug targets. In previous studies we showed that 2′,3′-(O)-(N-methylanthraniloyl) (MANT)-substituted nucleotides are potent AC inhibitors. The aim of this study was to provide systematic structure-activity relationships for 21 (M)ANT-substituted nucleotides at the purified catalytic AC subunit heterodimer VC1:IIC2, the VC1:VC1 homodimer and recombinant ACs 1, 2 and 5. (M)ANT-nucleotides inhibited fully activated VC1:IIC2 in the order of affinity for bases hypoxanthine > uracil > cytosine > adenine ∼ guanine xanthine. Omission of a hydroxyl group at the 2′ or 3′-position reduced inhibitor potency as did introduction of a γ-thiophosphate group or omission of the γ-phosphate group. Substitution of the MANT-group by an ANT-group had little effect on affinity. Although all nucleotides bound to VC1:IIC2 similarly according to the tripartite pharmacophore model with a site for the base, the ribose, and the phosphate chain, nucleotides exhibited subtle differences in their binding modes as revealed by fluorescence spectroscopy and molecular modelling. MANT-nucleotides also differentially interacted with the VC1:VC1 homodimer as assessed by fluorescence spectroscopy and modelling. Similar structure-activity relationships as for VC1:IIC2 were obtained for recombinant ACs 1, 2 and 5, with AC2 being the least sensitive AC isoform in terms of inhibition. Overall, ACs possess a broad base-specificity with no preference for the "cognate" base adenine as verified by enzyme inhibition, fluorescence spectroscopy and molecular modelling. These properties of ACs are indicative for ligand-specific conformational landscapes that extend to the VC1:VC1 homodimer and should facilitate development of non-nucleotide inhibitors.
KW - Adenylyl Cyclase
KW - Conformational landscape
KW - Fluorescence spectroscopy
KW - MANT-nucleotides
KW - Molecular modelling
UR - http://www.scopus.com/inward/record.url?scp=79960380978&partnerID=8YFLogxK
U2 - 10.1016/j.bcp.2011.05.010
DO - 10.1016/j.bcp.2011.05.010
M3 - Article
C2 - 21620805
AN - SCOPUS:79960380978
SN - 0006-2952
VL - 82
SP - 358
EP - 370
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
IS - 4
ER -