Humanized antibody specific to bacillus anthracis protective antigen and preparation method thereof

A method for preparing a humanized antibody specific to a Bacillus anthracis protective antigen, comprising the steps of:

• (a) preparing an antibody library by synthesizing an antibody to the Bacillus anthracis protective antigen;
• (b) selecting a Bacillus anthracis protective antigen antibody clone as an antibody that specifically binds to the Bacillus anthracis protective antigen from the antibody library;
• (c) expressing and purifying a Bacillus anthracis protective antigen monoclonal antibody by introducing an expression vector containing a gene of the Bacillus anthracis protective antigen antibody clone selected in step (b) into an antibody expressing host cell;
• (d) preparing a humanized antibody library of the Bacillus anthracis protective antigen containing complementarity-determining regions of an antibody using the Bacillus anthracis protective antigen monoclonal antibody as a template;
• (e) selecting a humanized antibody clone of the Bacillus anthracis protective antigen as an antibody specifically binding to the Bacillus anthracis protective antigen from the humanized antibody library of the Bacillus anthracis protective antigen;
• and
• (f) preparing a humanized antibody specific to the Bacillus anthracis protective antigen by introducing an animal cell expression vector containing the gene of the humanized antibody clone of the Bacillus anthracis protective antigen selected through step (e) into the antibody expressing host cell.

A humanized antibody specific to a Bacillus anthracis protective antigen or a fragment thereof comprising:

• a light chain or a fragment thereof comprising:
• a light chain CDR1 represented by an amino acid sequence of SEQ ID NO:
• 5;
• a light chain CDR2 represented by an amino acid sequence of SEQ ID NO:
• 6;
• and
• a light chain CDR3 represented by an amino acid sequence of SEQ ID NO:
• 7;
• and/or
• a heavy chain or a fragment thereof comprising:
• a heavy chain CDR1 represented by an amino acid sequence of SEQ ID NO:
• 8;
• a heavy chain CDR2 represented by an amino acid sequence of SEQ ID NO:
• 9;
• and
• a heavy chain CDR3 represented by an amino acid sequence of SEQ ID NO:
• 10.