Compound as reactive (2)
L-idonate + NAD+ → 5-dehydro-D-gluconate + NADH + H+
L-idonate + NADP+ → 5-dehydro-D-gluconate + NADPH + H+
Compound as product (1)
NAD(P)H + 2-keto-L-gulonate + H+ → NAD(P)+ + L-idonate
Reversible reaction (3)
NAD(P)+ + L-idonate ↔ 5-dehydro-D-gluconate + NAD(P)H + H+
NADPH + 2-keto-D-gluconate + H+ ↔ L-idonate + NADP+
L-idonate + NADP+ ↔ NADPH + 2-keto-L-gulonate + H+