title: Discovery of inhibitors of lupin diadenosine 5',5'''-P(1),P(4)-tetraphosphate hydrolase by virtual screening.
abstract: Novel inhibitors of lupin diadenosine 5',5'''-P(1),P(4)-tetraphosphate (Ap(4)A) hydrolase have been identified by in silico screening of a large virtual chemical library. Compounds were ranked on the basis of a consensus from six scoring functions. From the top 100 ranked compounds six were selected and initially screened for inhibitory activity using a single concentration isothermal titration calorimetry assay. Two of these compounds that showed excellent solubility properties were further analyzed, but only one [NSC51531; 2-((8-hydroxy-4-(4-methyl-2-sulfoanilino)-9,10-dioxo-9,10-dihydro-1-anthracenyl)amino)-5-methylbenzenesulfonic acid] exhibited competitive inhibition with a K(i) of 1 microM. A structural analogue of this compound also exhibited competitive inhibition with a comparable K(i) of 2.9 microM. (1)H, (15)N NMR spectroscopy was used to map the binding site of NSC51531 on lupin Ap(4)A hydrolase and demonstrated that the compound bound specifically in the substrate-binding site, consistent with the competitive inhibition results. Binding of NSC51531 to the human form of Ap(4)A hydrolase is nonspecific, suggesting that this compound may represent a useful lead in the design of specific inhibitors of the plant-like form of Ap(4)A hydrolases.
authors: Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.
authors: Kim M
authors: KM
authors: Branson
authors: Haydyn D T
authors: HD
authors: Mertens
authors: James D
authors: JD
authors: Swarbrick
authors: Jamie I
authors: JI
authors: Fletcher
authors: Lukasz
authors: L
authors: Kedzierski
authors: Kenwyn R
authors: KR
authors: Gayler
authors: Paul R
authors: PR
authors: Gooley
authors: Brian J
authors: BJ
authors: Smith
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002151:Calorimetry; D020134:Catalytic Domain; D003198:Computer Simulation; D015226:Dinucleoside Phosphates / Q000737:chemistry / Q000378:metabolism; D055808:Drug Discovery; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D031297:Lupinus / Q000201:enzymology*; D008958:Models, Molecular; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010940:Plant Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation
chemical_list: D015226:Dinucleoside Phosphates; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D010940:Plant Proteins; D010975:Platelet Aggregation Inhibitors; C020733:diadenosine tetraphosphate; D017766:Acid Anhydride Hydrolases; C020023:bis(5'-nucleosyl)tetraphosphatase (asymmetrical)