preferred_name: tetracycline(out) + H(+)(in) => tetracycline(in) + H(+)(out)
preferred_name_lc: tetracycline(out) + h(+)(in) => tetracycline(in) + h(+)(out)
label: tetracycline(out) + H(+)(in) => tetracycline(in) + H(+)(out)
label_lc: tetracycline(out) + h(+)(in) => tetracycline(in) + h(+)(out)