Growth Hormones: Expression, Structure and Protein Engineering

The growth hormones (GHs) are polypeptide hormones with molecular weight of 22 kD consisting of one chain. GHs are synthesized in an anterior lobe of hypophysis as a precursors with molecular weight of 25 kD. These hormones are necessary for the normal growth and development of organism and play an essential role in regulation of anabolic processes. The characteristic features of GHs are species specificity and multiple biological activity. Cloning and sequencing of DNA complementary to the rat GH messenger RNA in 1977 represented one of the first mammalian cDNA to be analyzed (Seeburg et al, 1977). Since then a variety of cDNAs corresponding to members of GH family from different vertebrates have been isolated and analyzed. These cDNAs have been used to produce the hormones in bacteria and eucaryotic cells by recombinant DNA techniques.