| 摘要 |
PURPOSE:To obtain an inexpensive new polypeptide having a structure obtained by replacing a part of amino acids of a human granulocyte colony stimulating factor polypeptide with other amino acids or depleting a part of amino acids from the polypeptide, exhibiting high activity and useful for the treatment and prevention of infectious diseases, leukemia, etc. CONSTITUTION:A cDNA coding a human granulocyte colony stimulating factor (hG-CSF) separated from a normal human peripheral blood macrophage is subjected to site-specific mutation with a restriction enzyme or T4DNA ligase to prepare a DNA fragment coding an amino acid sequence characterized by the replacement of a part of amino acids of the hG-CSF polypeptide with other amino acids and/or the depletion of a part of amino acids from the polypeptide. The fragment is linked to a proper vector and the obtained recombinant plasmid is introduced into a host such as E.coli. The obtained transformant is cultured to obtain the objective new polypeptide expressed by formula I (R<1> is a peptidyl group, etc., of formula II, etc.; R<2> is Cys, Ser, Ala or Thr) and having high hG-CSF activity. |
