title: pH opposite effects on synthesis of dinucleoside polyphosphates and on oxidation reactions catalyzed by firefly luciferase.
abstract: Previous results have shown that an oxidizing product of firefly luciferin, dehydroluciferyl-adenylate, is the main intermediate in the process of synthesis of dinucleoside polyphosphates catalyzed by firefly luciferase (EC 1.13.12.7). However, we have found that the pH effects on the luciferase oxidizing processes and on the synthesis of dinucleoside polyphosphate are opposite: acidic assay media enhance the synthesis of dinucleoside polyphosphate and inhibit the oxidizing processes. The reason for this apparent contradiction lies on the activation effect of low pH on the adenylate transfer reaction from dehydroluciferyl-adenylate to the acceptor nucleotide.
authors.affiliation: LAQUIPAI, Chemistry Department, Faculdade de Ciências, Universidade do Porto, R. Campo Alegre 687, 4169-007, Porto, Portugal.
authors.forename: Hugo
authors.initials: H
authors.lastname: Fraga
authors.forename: Joaquim C G
authors.initials: JC
authors.lastname: Esteves da Silva
authors.forename: Rui
authors.initials: R
authors.lastname: Fontes
mesh_terms: D000818:Animals; D002384:Catalysis; D001517:Coleoptera; D015226:Dinucleoside Phosphates / Q000138:chemical synthesis*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008156:Luciferases / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D015226:Dinucleoside Phosphates; C020733:diadenosine tetraphosphate; C053244:adenosine 5' P(1)-tetraphosphate-P(4)-5'''-cytidine; D008156:Luciferases