Hydrolysis of carbamoyl and sulfocarbamoyl esters of paralytic shellfish toxins. Ester hydrolysis is unaffected by the presence or absence of a hydroxyl moiety at the N-1 postion of the substrate toxin but is significantly affected by the stereochemistry of sulfate esters at C-11 of the substrate toxin. Strongly inhibited by the serine proteinase inhibitors BSF and AEBSF. Weakly inhibited by the proteinase inhibitors bestatin and E-64, and by the serine proteinase inhibitor leupeptin. Not inhibited by EDTA or by the proteinase inhibitor aprotinin. Optimum pH is 7.0. Activity decreases sharply with increasing acidity or alkalinity. Optimum temperature is 20 degrees Celsius and activity decreases sharply above 40 degrees Celsius. Homodimer. Ubiquitous (at protein level). Highest levels of expression in digestive gland and crystalline style. Glycosylated.