A selective extraction of growth hormone from bovine pituitary gland and its further purification and crystallization

A highly efficient method for the isolation of bovine growth hormone (GH) is described. The method is based on selective extraction of GH from 15,000 g subcellular sediment of anterior pituitary gland with 130-150 mM NH4HCO3, 1 mM EGTA, pH 7.2-7.4, at 2-6 degrees C for 60 min, purification of the extracted GH by ammonium sulfate fractionation, one-step ion-exchange column chromatography on DEAE-cellulose (or CM-cellulose), and gel filtration on Sephadex G-75. This 2-3 day procedure provides a highly pure hormone in high yield (up to 70-80 mg per 35-40 g of the whole pituitary gland), which can be crystallized by the batch method at a low ionic strength and isoelectric pH.