Purification and the immunological characterization of rat protein phosphatase 2A: enzyme levels in diabetic liver and heart.

Abstract

Protein phosphatase 2A1 was purified from rat skeletal muscle and used to produce antisera to the three subunits of the holoenzyme. Affinity purified antibodies specific for the subunits of the phosphatase enzyme were found to recognize the type 2A1 and 2A2 phosphatase from rat skeletal muscle, heart, liver, brain and erythrocytes and were used to investigate the effects of diabetes on the levels of this enzyme in liver and heart. Phosphorylase phosphatase assays coupled with immunoblot analysis of fractionated rat liver and heart cytosol from normal and diabetic animals show no apparent differences in the quantity or activity of these enzymes following the induction of alloxan diabetes. When considering these results and the normal physiological concentrations of known effectors of these enzymes, it is likely that protein phosphatase 2A1 and 2A2 are not responsible for the dephosphorylation of phosphorylase a under physiological conditions.

• Authors: S R Jaspers, T B Miller Jr
• Journal: Molecular and cellular biochemistry (Mol Cell Biochem) Vol. 101 Issue 2 Pg. 167-74 (Mar 13 1991) ISSN: 0300-8177 [Print] Netherlands
• PMID: 1650427 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Alloxan
• Phosphoprotein Phosphatases
• Protein Phosphatase 2

Topics

• Alloxan
• Animals
• Cytosol (enzymology)
• Diabetes Mellitus, Experimental (chemically induced, complications, enzymology)
• In Vitro Techniques
• Organ Specificity
• Phosphoprotein Phosphatases (immunology, isolation & purification)
• Protein Phosphatase 2
• Rats