| Abstract: | The application of different approaches for preparing DNAs coding for peptide hormones was demonstrated. The libraries of human, bovine and porcine pituitaries cDNA were obtained starting from their total mRNAs. Screening of these libraries revealed clones containing human, bovine and porcine growth hormone sequences, cDNAs for bovine ACTH-beta-lipotropin precursor and for bovine and porcine prolactin. The gene of human calcitonin was created by combination of chemical and enzymatic synthesis. This synthetic gene was further cloned in pBR322. The expression of cloned human growth hormone cDNA under control of different Escherichia coli promoters was studied and physico-chemical and biological properties of the growth hormone produced by E. coli were tested. |
