Synthesis, purification and biological evaluation of porcine corticotropin-releasing factor.
The 41-residue sequences of recently identified porcine corticotropin-releasing factors [Ile40]pCRF and [Asn40]pCRF were assembled on a benzhydrylamine resin support. Deprotection and cleavage from the resin were accomplished by HF treatment. The crude peptides were purified by HPLC. The homogeneity of the final materials, obtained in 0.2% and 0.4% overall yield for [Ile40]pCRF and [Asn40]pCRF respectively, was assessed after the isolation by HPLC and amino acid analysis. Both sequences of the synthetic 41-residue pCRF stimulated the release of corticotropin (ACTH) from superfused rat pituitary cells on a column, the responses being related to a log-dose of CRF in the range of 1-20 ng/ml. [Ile40]pCRF and [Asn40]pCRF also augmented the in vivo release of ACTH in rats pretreated with chlorpromazine, morphine and Nembutal. [Ile40]pCRF appeared to be equipotent to ovine CRF and about twice as active as [Asn40]pCRF. The data indicate that synthetic porcine [Ile40]pCRF and [Asn40]pCRF have high biological activity.
D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003346:Corticotropin-Releasing Hormone / Q000138:chemical synthesis* / Q000302:isolation & purification / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism; D013552:Swine
D000596:Amino Acids; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone