preferred_name: Mn(2+)(out) + n H(+)(in) => Mn(2+)(in) + n H(+)(out)
preferred_name_lc: mn(2+)(out) + n h(+)(in) => mn(2+)(in) + n h(+)(out)
label: Mn(2+)(out) + n H(+)(in) => Mn(2+)(in) + n H(+)(out)
label_lc: mn(2+)(out) + n h(+)(in) => mn(2+)(in) + n h(+)(out)