121. Isolation and characterization of poly(A)mRNP particles from the bovine adrenol cortex and their relationship to an endogenous polysomal protein kinase

Abstract

Oestrogens can be grouped into two classes, based on their structural characteristics and biological activities; the typical oestrogens exemplified by the steroidal and the stilbene types, and the atypical oestrogens by the triaryl-ethylene types. In order to gain an understanding into the relationship between molecular structure and biological activity of oestrogens, receptor affinity, uterotrophic and antiimplantation activities of various 5,6-seco- and 9,11-seco-oestradiols, representing flexible analogues of the parent prototype, and certain 3-phenyl-4-aryl-chromenes and -chromans, representing triaryl-ethylene and -ethane prototypes incorporated into a rigid framework, have been studied.Comparative receptor affinity and biological activity of the seco-oestradiol analogues revealed the importance of the features of planarity and molecular rigidity of oestradiol-17β for its high affinity to the receptor, and also led to a better appreciation of the characteristics of the receptor regions involved in binding around C-3, C-8, C-9 and C-18 of oestradiol.The results of the study on chromenes and chromans indicated that in triaryl-ethylene oestrogens, t-aminoalkoxy-phenyl residue plays an important role in receptor binding and biological activity. A study of the influence of alkyl groups at C-2 of the chromene and chroman analogues revealed noteworthy information about the general stereochemical requirements of these molecules for an optimum receptor fit.A consideration of these results and the findings previously reported in literature point to the possibility that all the molecular types considered here, interact with a common binding site of the receptor, albeit in a different stereochemical fashion, which may be one of the reasons for the differences in their biological activities.