Acid phosphatases from liver of Rana esculenta. Subcellular localization and partial characterization of multiple forms

1. Four acid phosphatases (AcPase I, II, III and IV) were found in the liver of the frog Rana esculenta. 2. AcPases I, II, III, and IV were associated with the microsomal, mitochondrial-lysosomal, nuclear and soluble fractions respectively and showed apparent molecular weights of about 240,000, 110,000, 38,000 and 17,000. 3. All the enzymes show acid pH optima, and similar Km values for p-nitrophenylphosphate. 4. AcPases I, II, and III hydrolyze most of the common phosphate esters whereas AcPase IV hydrolyzes effectively only p-nitrophenylphosphate, phenylphosphate and flavine mononucleotide. 5. AcPases I and II are inhibited by NaF and tartrate. AcPases III and IV are tartrate resistant. 6. Temperature inhibits AcPases I, II, IV, whereas it activates AcPase III.