IMMUNOGENIC DETOXICATED VARIANT OF CHOLERA TOXIN AND IMMUNOGENIC DETOXICATED VARIANT OF TOXIN LT, THEIR PREPARATION, AND THEIR USE FOR PREPARING VACCINE

摘要

PROBLEM TO BE SOLVED: To prepare a vaccine made from a genetically detoxicated single antigen as a toxoid derived from CT(cholera toxin) or LT(heat-labile toxin) and affording entire prevention from cholera or toxinogenic Escherichia coli due to a secondary product. SOLUTION: The objective variant is an immunogenic detoxicated protein including the amino acid sequence of cholera toxin subunit A (CT-A) or a fragment thereof or the amino acid sequence of Escherichia coli LT subunit A (LT-A) or a fragment thereof, wherein Val-53, Val-97, Tyr-104 or Ser-63 or an amino acid lying at the position corresponding thereto is substituted by another amino acid.