Studies on the Enzymatic and Chemical Inactivation of Hypothalamic Follicle-Stimulating Hormone-Releasing Hormone

Abstract

The effect of chemical and enzymatic treatments on the biological activity of porcine follicle-stimulating hormone-releasing hormone (FSH-RH) was studied. FSH-RH activity was not affected by trypsin, pepsin, neuraminidase, carboxy-peptidase A and aminopeptidase M. However, incubationwith chymotrypsin, subtilisin and papain abolished the FSH-RH activity as did treatment with performic acid, hydrochloric acid (0.9 M, 1 h, 100 °C), diazotized sulfanilic acid and N-bromosuccinimide. Nitrous acid, sodium metaperiodate and ninhydrin did not affect the FSH-RH activity appreciably. These results, together with previous information obtained during purification procedures, indicate that FSH-RH is a small basic polypeptide. Tyrosine, histidine, or tryptophan are probably present in the molecule and may be necessary for the biological activity.