preferred_name: a dipeptide(out) + H(+)(out) <=> a dipeptide(in) + H(+)(in)
preferred_name_lc: a dipeptide(out) + h(+)(out) <=> a dipeptide(in) + h(+)(in)
label: a dipeptide(out) + H(+)(out) <=> a dipeptide(in) + H(+)(in)
label_lc: a dipeptide(out) + h(+)(out) <=> a dipeptide(in) + h(+)(in)