Chang R C, Huang W Y, Arimura A, Redding T W, Coy D H, Saffran M, Kong A, Hamilton J W, Cohn D V, Schally A V
Horm Metab Res. 1981 Apr;13(4):228-32. doi: 10.1055/s-2007-1019228.
Significant CRF activity was found in a fraction with Rf = 0.82-0.7 or VE/VT = 0.41-0.48 obtained by gel filtration of acid extracts of pig hypothalami on Sephadex G-25. The activity of this fraction decreased markedly during subsequent purification, particularly in the last two steps. From this fraction, a heptapeptide with significant ACTH releasing activity in vitro, was isolated in pure state, and its amino acid sequence was established as H-Phe-Ile-Tyr-His-Ser-Tyr-Lys-OH. This heptapeptide was synthesized by solid phase methods. The CRF activity of synthetic heptapeptide in vitro was low but could be potentiated by a cofactor fraction from rat hypothalamic extract.
