Methods are described for the demonstration of one acid phosphatase in the nucleolini and nucleoplasm and another in the cytoplasm of cultured diploid and aneuploid mammalian cells. The pH optimum of the nucleolinar and nuclear acid phosphatase is 4.8-5.0, while that of the cytoplasmic enzyme is 5.6 and the enzymes differ in sensitivity to various inhibitors. The topography of acid phosphatase activity within the nucleolus of untreated cells is similar to that of nucleolinar RNP and the substance stained by lead precipitation. A redistribution or selective loss of one or more of these components occurs in pathological states. Acid phosphatase activity was also stained and demonstrated biochemically in isolated nuclei and nucleoli. Evidence is presented to exclude the possibility that nuclear and nucleolinar staining by the lead glycerophosphate methods presented here is due to non-enzymatic hydrolysis of the substrate, diffusion from the cytoplasm or selective affinity of these structures for lead.
All Science Journal Classification (ASJC) codes
- Cell Biology