title: Evaluation of histochemical observations of activity of acid hydrolases obtained with semipermeable membrane techniques. 3. The substrate specificity of isoenzymes of acid phosphatase in m.gastrocnemius of rabbits.
abstract: Three distinct isoenzymes of acid phosphatase have been separated from extracts of m.gastrocnemius of normal and of vitamin E deficient rabbits by gel filtration and polyacrylamide gel electrophoresis. These isoenzymes, termed I, II and III, have molecular weights of: 110,000--130,000, 60,000--78,000 and 12,500--14,500. Isoenzymes I and II split the substrates 4-methylumbelliferyl phosphate and naphthol AS-BI phosphate and the activity is strongly increased in the muscles of vitamin E deficient rabbits. Isoenzyme III splits only 4-methylumbelliferyl phosphate and the activity is not increased in the muscles of vitamin E deficient rabbits. The pH-optimum for isoenzymes I and II is 4.8 and for isoenzyme III 5.5. It has been shown that the histochemical semipermeable membrane technique, using substrate naphthol AS-BI phosphate, is a very reliable technique for demonstrating activity of the isoenzymes I and II in tissue sections. On the other hand, activity of isoenzyme III cannot be demonstrated with this histochemical technique. In pathologically altered muscles, the activity of the isoenzymes I and II is greatly increased whilst the activity of isoenzyme III is not significantly altered.
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis / Q000378:metabolism*; D000818:Animals; D005121:Extremities; D005966:Glucuronidase / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000032:analysis / Q000378:metabolism*; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology*; D011817:Rabbits; D013379:Substrate Specificity; D014811:Vitamin E Deficiency / Q000201:enzymology*
chemical_list: D007527:Isoenzymes; D000135:Acid Phosphatase; D005966:Glucuronidase