Follicle-stimulating Hormone-releasing Hormone Research Articles

Further studies on the enzymatic and chemical inactivation of hypothalamic FSH-RH.

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, carboxypeptidase A, aminopeptidase M and leucine aminopeptidase. However, incubation with chymotrypsin, subtilisin, papain and pyrrolidone carboxylyl peptidase abolished the FSH-RH activity as did treatment with 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. Amino acid analyses of the purest FSH-RH preparation showed the following composition: His 1, Arg 1, Ser 1, Glu 1, Pro 1, Gly 2, Leu 1, Trp 1, and Tyr 1. These results and information obtained during purification procedures indicate that a basic polypeptide composed of ten amino acids possesses both LH-RH and FSH-RH activity.

Studies on the enzymatic and chemical inactivation of hypothalamic follicle-stimulating hormone-releasing hormone.

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.

Evidence for peptide nature of LH and FSH-releasing hormones

The effects of several chemical and enzymatic treatments on the biological activity of highly purified porcine luteinizing hormone-releasing hormone (LH-RH) and follicle-stimulating hormone-releasing hormone (FSH-RH) (1) were studied in an attempt to define the chemical nature of these hypothalamic hormones. The results obtained are consistent with the concept that LH-RH/FSH-RH activity is due to small basic polypeptide(s), but a conclusive differentiation between LH-RH and FSH-RH cannot yet be made.