Abstract
The enzyme responsible for the desulphation of porphyran by extracts of Porphyra umbilicalis has been purified 22-fold by adsorption on calcium phosphate gel followed by elution with sodium acetate. A turbidimetric assay method has been developed. The effect on the enzyme of pH and of various activators and inhibitors has been studied. It is dependent on the presence of a bi- or ter-valent cation, which is not Mg2+, and is markedly activated by borate.