alpha-maltoheptaose + phosphate <=> alpha-maltohexaose + alpha-D-glucose 1-phosphate
alpha-maltoheptaose + phosphate <=> alpha-maltohexaose + alpha-d-glucose 1-phosphate
alpha-maltoheptaose + phosphate <=> alpha-maltohexaose + alpha-D-glucose 1-phosphate
alpha-maltoheptaose + phosphate <=> alpha-maltohexaose + alpha-d-glucose 1-phosphate