| 摘要 |
PURPOSE:To obtain a human calcitonin polymerized protein, having lowering action on blood serum Ca ion level and capable of providing a large amount of calcitonin useful for treating osteoporosis, etc., by expressing a tandem.repeat type gene coding a human calcitonin precursor and preparing the protein. CONSTITUTION:A recognition sequence with a restriction enzyme required to polymerize a gene is added to the upstream and the downstream sides of the gene capable of coding a human calcitonin precursor and plural genes capable of coding a human calcitonin precursor peptide are connected and linked to an expression vector to prepare a tandem.repeat type gene, which is then transduced into a host such as Escherichia coli to transform the host. The obtained transformant is subsequently cultured in a culture medium to collect the resultant product and afford the objective human calcitonin polymerized protein having an amino acid sequence expressed by formula I [X is peptide of amino acid sequence of amino acid Nos. 1 to 33 expressed by formula II (33E of Xaa is Gly, Leu, Ile, etc.; 34E is Arg or Glu); alpha, beta and gamma are recognition sequences of restriction enzyme; delta is Arg or Glu; (N) is N-terminal; (C) is C- terminal]. |
