Synthesis of novel alkyl triphosphates and their substrate properties toward terminal deoxynucleotidyltransferase

Novel triphosphate derivatives bearing bulky or small groups at alpha-position attached to the triphosphate residue through linkers of different structures and lengths were synthesized and studied as substrates toward terminal deoxynucleotidyltransferase. The substrate efficacy depends on the structure of substituents, linker length, and nature of metal activator. The replacement of hydrophobic groups by small substituents decreased the substrate efficacy by about 20 times in respect to hydrophobic residues. The dependence on metal activator is the following: Co(2+) > Mn(2+) >> Mg(2+). The model of interaction of alkyl triphosphates with linkers of different lengths bearing TdT active site is presented.