Method for improving antibody stability

Abstract

Herein is reported a method for selecting or deselecting an antibody comprising a) determining for each Asp and Asn residue in an antibody Fv region the conformational flexibility of the Cα-atom using a homology model ensemble, b) determining for each Asp and Asn residue in an antibody Fv region the size of the amino acid residue C-terminal to the Asp or Asn residue, and c) selecting an antibody in which the Ca-atom is conformationally inflexible and/or the Asp or Asn has a big C-terminal amino acid residue, or deselecting an antibody in which the Cα-atom has a moderate to high conformational flexibility and/or the Asp or Asn has a small C-terminal amino acid residue.

1 - 6 . (canceled) 
     
     
         7 . A method for producing an antibody comprising the following steps:
 a) cultivating a mammalian cell comprising a nucleic acid encoding an antibody that has been selected with a method according to any one of claims  1 ,  3 ,  5  and  6 ,   b) recovering the antibody from the cell or the cultivation medium and thereby producing the antibody.   
     
     
         8 . The method according to  claim 7 , characterized in that the conformational flexibility is the root mean square deviation (RMSD) of the respective Asn/Asp residues' C α -atoms in the homology model ensemble. 
     
     
         9 . The method according to  claim 8 , characterized in that
 i) conformational inflexible is a RMSD of 0.01 Å or less,   ii) conformational flexible is a RMSD of more than 0.01 Å,   iii) conformational moderate flexible is a RMSD between 0.145 Å and 0.485 Å, and   iv) conformational highly flexible is a RMSD of more than 0.485 Å.   
     
     
         10 . The method according to  claim 7 , characterized in that the homology model ensemble is made with the antibody Fv fragment. 
     
     
         11 . The method according to  claim 7 , characterized in that a small amino acid residue is Gly, Ala, Ser, Cys, or Asp. 
     
     
         12 . The method according to  claim 11 , characterized in that a small amino acid residue is Gly, Ala, Ser, or Cys.