What is "beta-porphyranase"

Beta-porphyranase (, porphyranase, PorA, PorB, endo-beta-porphyranase) is an enzyme with systematic name porphyran beta-D-galactopyranose-(1->4)-alpha-L-galactopyranose-6-sulfate 4-glycanohydrolase. This enzyme catalyses the following chemical reaction

Hydrolysis of beta-D-galactopyranose-(1->4)-alpha-L-galactopyranose-6-sulfate linkages in porphyran

The backbone of porphyran consists largely (~70%) of (1->3)-linked beta-D-galactopyranose followed by (1->4)-linked alpha-L-galactopyranose-6-sulfate.