preferred_name: L-threonine(in) + H(+)(out) => L-threonine(out) + H(+)(in)
preferred_name_lc: l-threonine(in) + h(+)(out) => l-threonine(out) + h(+)(in)
label: L-threonine(in) + H(+)(out) => L-threonine(out) + H(+)(in)
label_lc: l-threonine(in) + h(+)(out) => l-threonine(out) + h(+)(in)