We synthesized [3′-3H]-5,6,7,8-tetrahydrobiopterin from [8,5′-3H]guanosine 5′-triphosphate ([8,5′-3H]GTP) using GTP cyclohydrolase (EC 3.5.4.16), 6-pyruvoyltetrahydropterin synthase and sepiapterin reductase (EC 1.1.1.153). After purification by cation-exchange h.p.l.c. a solution of radiochemically pure (> 95%) [3′-3H]-5,6,7,8-tetrahydrobiopterin with a specific activity of 9.2 Ci/mmol was obtained. The product proved well suited for studying the binding of tetrahydrobiopterin to nitric-oxide synthase.
我们使用GTP环化酶(EC 3.5.4.16)、6-吡酰基四氢生物蝶呤合成酶和丝氨酸还原酶(EC 1.1.1.153)从[8,5'-3H]鸟苷三磷酸([8,5'-3H]GTP)合成了[3'-3H]-5,6,7,8-四氢生物蝶呤。在阳离子交换高效液相色谱纯化后,得到放射化学纯度(>95%)和比活度为9.2 Ci / mmol的[3'-3H]-5,6,7,8-四氢生物蝶呤溶液。该产品非常适合研究四氢生物蝶呤与一氧化氮合酶的结合。