4-hydroxybutanoate + NADP(+) <=> succinate semialdehyde + NADPH + H(+)
4-hydroxybutanoate + nadp(+) <=> succinate semialdehyde + nadph + h(+)
4-hydroxybutanoate + NADP(+) <=> succinate semialdehyde + NADPH + H(+)
4-hydroxybutanoate + nadp(+) <=> succinate semialdehyde + nadph + h(+)