label: lactose + GDP-beta-L-fucose <=> beta-D-galactosyl-(1->4)-[alpha-L-fucosyl-(1->3)]-D-glucose + GDP + H(+)
label_lc: lactose + gdp-beta-l-fucose <=> beta-d-galactosyl-(1->4)-[alpha-l-fucosyl-(1->3)]-d-glucose + gdp + h(+)