Specific features of phosphomonoesterase of Entamoeba histolytica (NIH-200).

Axenically grown E. histolytica possess significant acid phosphatase activity. The Km of the enzyme was found to be 7.1 x 10(-3) and was maximally active at pH 4.5. Acid phosphatase activity was significantly inhibited by Cu2+, cysteine and was activated by tartrate and fluoride. It was found that E. histolytica acid phosphatase differs in some properties as compared to the enzyme reported from other sources.