[Theoretical analysis of the amino acid sequence of receptors for growth hormones and prolactins. Prediction of ligand-binding segments].

At present the growth hormone and prolactin receptors were cloned along with their variant forms from human, rat, mouse, rabbit, bovine and sheep tissues. The functional topography of receptors is practically unknown. Because of the high price and difficulty of protein's total mutagenesis, it is reasonable to carry on a theoretical analysis of structures of receptors to predict the most probable ligand-binding sites. We studied the primary structures of known prolactin and growth hormone receptors using theoretical methods proved to be powerful in earlier structure--activity relationship investigations. We analyzed the secondary structure, conservative positions, hydrophilicity profiles of the growth hormone and prolactin receptors, and used the original method based on information theory to predict the sites which are promising for mutagenesis or peptide synthesis as probable ligand-binding sites. Three segments corresponding to the main conservative, hydrophilic and rare sites were predicted to form the ligand-binding determinant.