D-maltotetraose + H2O <=> D-maltotriose + alpha-D-glucose
d-maltotetraose + h2o <=> d-maltotriose + alpha-d-glucose
D-maltotetraose + H2O <=> D-maltotriose + alpha-D-glucose
d-maltotetraose + h2o <=> d-maltotriose + alpha-d-glucose