Venomexonuclease(PhosphodiesteraseI)successivelyhydrolyzes5-mononucleotidesfrom3-OH-terminatedribo-anddeoxyribo-oligonucleotides.TheenzymehasanoptimalpHrangeof9.8-10.4andamolecularweightofkDa.Phosphodiesteraseisinhibitedbyreducingagentssuchasglutathione,cysteineandascorbicacids.Itis