| 摘要 |
PURPOSE:To obtain a variant, capable of purely producing the abrin A chain having a high activity in a large amount and useful as a raw material, etc., for medicines such as an antibody-based complex by inserting serine, etc., into an amino acid at a specific position of a natural type abrin A chain. CONSTITUTION:This abrin A chain variant is obtained by inserting serine or alanine into an amino acid at the 202nd position of a natural type abrin A chain and has an amino acid sequence such as sequence table 1. Furthermore, the abrin A chain variant is obtained by joining DNA fragments capable of coding the abrin A chain variant under control of a genetic expression system of Escherichia coli, providing a recombinant plasmid, culturing the Escherichia coil transformed by the recombinant plasmid, producing the abrin A chain variant and recovering the abrin A chain variant from the microbial cell. |
