Regulation of polymerase using cofactor oxidation states

Abstract

Polynucleotide synthesis performed with a template independent polymerase such as terminal deoxynucleotidyl transferase (TdT) is regulated by controlling the oxidation state of a metal cofactor. The oxidation state of the metal cofactor is changed to +2, thus activating the polymerase, by applying a voltage with electrodes or by introducing a chemical redox reagent. Addressable polynucleotide synthesis creates polynucleotides with different arbitrary sequences through use of spatial control of cofactor oxidation states to add nucleotides only at selected locations on an array. Control of metal oxidation states is regulated by selective activation of a microelectrode array, controlled addition of redox reagents to specific locations on the array, or controlled activation of photocatalysts at specific locations on the array. Scavengers in solution prevent cofactors distant from the selected locations from catalyzing polymerase activity and thereby maintain the localized effect of polymerase activation.