Background of the antigen
Phosphatase enzymes catalyse hydrolysis of phosphoric acid esters of various alcohols, e.g. a hexose phosphate, to yield the alcohol and free inorganic phosphate. This may be a way of recycling phosphate in the cell, and the level of phosphate may be elevated under conditions of phosphate starvation (in algae for example). Acid phosphatases have pH optima below 7, whereas alkaline phosphatases are most active above pH 7. Commercial quantities of acid phosphatase are obtained from plant sources e.g. potato and wheat germ, whereas similar quantities of alkaline phosphatase are obtained from animal intestine and bacteria.
