[Isolation, purification and characterization of porcine brain calmodulin]

The calmodulin has purified by heating, phenyl-Sepharose affinity chromatography, DEAE-cellulose chromatography and Sephadex G50 chromatography from the porcine brain and characterized. The results showed that the purified calmodulin appears just one band on PAGE slab with M.W. of 14.1 +/- 1.0 kd (containing 1 mmol/L CaCl2) and 16.9 +/- 1.2 kd (containing 1 mmol/L EGTA). Electrophoresis migration was distinctly different between the sample containing CaCl2 and the sample containing EGTA; pI = 4.35; the quantity of calmodulin required for half maximum activation of 2800 unit of PDE was 15ng. The purified calmodulin increased the activity of PDE and this action was inhibited by trifluoperazine. The yield was 4.2 mg/100g of the porcine brain.