Phosphate → Glyoxal 2'-deoxyguanosine

Glyoxal-2′-deoxyguanosine was synthesized from 2′-deoxyuridine and glyoxal-guanine under the following conditions, by using any one of the aforementioned three sets of enzyme solutions and the Bacillus stearothermophilus JTS 859 enzyme solution obtained in Production Example 2. Specifically, 5 mM phosphate buffer (pH 7) containing 30 mM 2′-deoxyuridine, 30 mM glyoxal-guanine, 100 mM boric acid, and 4 mM disodium ethylenediaminetetraacetate was first prepared.