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