Immunoreactive polypeptide and its production

PURPOSE: To produce an immunoreactive polypeptide by bonding a DNA fragment containing a gene coding for the subunit S 1 of anti-pertussigen to a cloning vector to form a hybrid plasmid. CONSTITUTION: A base sequence coding for a prescribed amino acid at one or more positions of a DNA molecule is substituted with a base sequence coding for a desired amino acid to denature a gene coding for the subunit S 1 of anti- pertussigen. The DNA fragment of the product is bonded to a cloning vector to form a hybrid plasmid. A host microorganism is transformed by the hybrid plasmid, the transformant is cultured in a proper medium and the objective immunoreactive polypeptide containing the denatured subunit S 1 is collected from the medium or the microbial cell. COPYRIGHT: (C)1989,JPO