Antigen-binding molecules, the antigen-binding activity of which varies according to the concentration of compounds, and libraries of said molecules

The present invention is a pharmaceutical composition comprising a targeted tissue specific antigen binding molecules, non-natural compounds antigens that the antigen-binding activity varies with the concentration of binding molecules, each different plurality of the antigen binding libraries, including the molecular art antigen-binding molecule, and that a task of providing a method of manufacturing the same, and the method for screening for antigen-binding molecules. The present inventors have found that, depending on the concentration of the low molecular weight compound and creating an antigen binding molecule comprising the antigen-binding domain or an antigen-binding domain that binding activity to the antigen changes, and further has respective different plurality of the antigen binding domain, or an antigen-binding domain by creating a library that contains a and found that the above problems can be solved by using the library. To cure various diseases resulting from the target tissue to target tissue-specific by use of antigen-binding molecules of the invention can be performed.