a 2,4-dihydroxypteridine + NH4(+) => a 2-amino-4-hydroxypteridine + H2O + H(+)
a 2,4-dihydroxypteridine + nh4(+) => a 2-amino-4-hydroxypteridine + h2o + h(+)
a 2,4-dihydroxypteridine + NH4(+) => a 2-amino-4-hydroxypteridine + H2O + H(+)
a 2,4-dihydroxypteridine + nh4(+) => a 2-amino-4-hydroxypteridine + h2o + h(+)