Identification and purification of factor B-GHRH from hypothalami which releases growth hormone
Johansson, K.N.; Currie, B.L.; Folkers, K.; Bowers, C.Y.
Biochemical and Biophysical Research Communications 60(2): 610-615
Exploratory purifications and assays of fractions for release of growth hormone (GH) revealed two separable entities each of which unambiguously released Gh by radioimmunoassay. They are provisionally designated factor A-Ghrh and factor B-Ghrh until they are chemically and biologically characterized. After initial steps of isolation from porcine hypothalami, factor B-Ghrh was extensively purified by stepwise chromatography using Bio-Gel P-2, Sephadex LH-20, Sephadex G-25 with a partition system of acetic acid-butanol-pyridine, DEAE-Sephadex A-25, and Bio-Gel CM-2. Assays showed that certain fractions were active, in vitro, at levels of ca. 15 μg. Factor B-Ghrh is inhibited by somatostatin.