Description
Acid phosphatase is an esterase with broad activity at an optimal pH below 7.0. There are three isozymes, EI, EII, and EIII of similar molecular weight (55 kDa± 5 kDa). Their optimum pH's are 5.5, 4.5, and 4.0 respectively. Acid phosphatase activity was observed by Teller Aladdin Library Archives in 1954 in preparations of a wheat germ lipase described by Singer JBC, 174, 11, in 1948. Equivalent commercial preparations have been distributed labeled as lipase and acid phosphatase thus generating some confusion. Subsequent work has confirmed that the non-specific esterase activity of the wheat germ preparation may be measured both as lipase (triacetin as substrate) and phosphatase. The enzyme assay is based on the work of Brandenberger and Hanson (Helv. Chim. Acta, 36, 900, 1953) and Hofstee ( Arch. Biochem. Biophys., 51, 239, 1954).Acid phosphatase (APase) non-specifically catalyzes the hydrolysis of monoesters and anhydrides of phosphoric acid to produce inorganic phosphate. It is used to study the production, transport, and recycling of phosphate and the metabolic and energy transduction processes of the cell.Characteristics of Acid Phosphatase from Wheat Germ:Molecular weight: 55,000 ± 5,000 (Verjee 1969).Composition: Three isozymes of closely similar molecular weights have been reported by Verjee (1969): EI, EII, and EIII. See also Brouillard and Ouellet (1965).Optimal pH: EI - 5.5, EII - 4.5, and EIII - 4.0. (Verjee 1969).Specificity: The enzyme has a broad esterase activity. See Joyce and Grisolia (1960). It shows highest activity for pyrophosphate.Inhibitors: Fluoride, molybdate and orthophosphate (Verjee 1969)