[An analysis of local similarities in the primary structures of protein hormones].

An analysis of primary structures for local similarities has been performed for a number of protein hormones. The statistical MacLachlan's technique and three matrices of amino acids similarities: in respect to the genetic code (M1), physico-chemical properties (M2), interchangeability of amino acids in homologous proteins (M3) have been used. When comparing prolactin and growth hormones, four zones of high structural similarity have been found. Comparison of beta-subunits of interstitial-cell and thyroid-stimulating hormones has shown two zones of high similarity. Using M3 matrice, non-homogeneity of the self local similarity of structure has been shown for prolactin, growth hormone, beta-lipotropin, proinsulin and parathormone. For the latter three hormones, the high evolutionary conservative regions coincide with the active sites of structure. It is suggested that such regions in the structures of prolactin and growth hormone also provide the active function.