Acid phosphatase electrophoretic behavior

Beckman et al. (28) have studied the electrophoretic separation of the acid phosphatase activity in tissue extracts on starch gel at pH 8. They described four electrophoretic bands A, B, C, and D. Table IV (28) shows the distribution of activity in different organ extracts. The ABD pattern predominated in kidney BD in liver, intestine, heart, and skeletal muscle B in skin and D in pancreas. The C component was present in a large number of placentae but not in other adult organs. All four electrophoretic components were inhibited by d-(- -)-tartrate A contained sialic acid, D had a lower pH optimum and was more heat resistant than A, B, and C. Components C and D showed parallel electrophoretic behavior. In human skin fibroblasts grown in tissue culture, the acid phosphatase was generally high and the most common pattern was BD. Almost every culture showed some activity. The BD... 

The phenotypes of erythrocyte acid phosphatase not only exhibit differences in electrophoretic behavior, but also show variation in total acid phosphatase activity. Spencer et al. (S26) studied the distribution of red cell phosphatase activities in hemolysates from 275 individuals with various phenotypes. The assay was performed with 0.01 M disodium p-nitrophenyl phosphate as substrate at pH 6.0 in citrate buffer. The units of activity were expressed as /unoles of p-nitrophenol liberated in 0.5 hour at 37°C per gram of hemoglobin. These results are shown in Table 5. 

The relationship between the various tissue alkaline phosphatases has been under discussion for many years (24). Bodansky established that inhibition by bile acids could be used to distinguish between intestinal and bone or kidney isoenzymes (25). The organ-specific behavior of rat tissue phosphatases toward a variety of compounds was investigated by Fishman (26). Of particular importance was the observation that l-phenylalanine is a stereospecific inhibitor for the intestinal isoenzyme (27). Immunochemical (28, 29) and electrophoretic techniques (30, 31) have shown that there are also physical differences between the tissue phosphatases. It is not yet clear what the precise nature of these differences is (32), although in part it results from a variability in sialic acid content. 

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