Patent ID: 8440413

Claim:
A screening method for selecting a test substance which strengthens a bond between a thioredoxin protein and a macrophage migration inhibition factor, comprising: mixing the test substance with a binding substance that is a naturally-occurring human thioredoxin protein, whose amino acid sequence is shown in SEQ ID NO: 1 and whose is -Cys-Gly-Pro-Cys (SEQ ID NO: 4), or a protein having an amino acid sequence of the polypeptide of the human thioredoxin protein in which one or both of the cysteines in the active site are mutated; bonding the binding substance to a naturally-occurring human macrophage migration inhibition factor; and monitoring a bond state between the binding substance mixed with the test substance and the naturally-occurring human macrophage migration inhibition factor compared to a bond state between a binding substance without being mixed with the test substance and the naturally-occurring human macrophage migration inhibition factor, thereby selecting the test substance having a stronger bond with the naturally-occurring human macrophage migration inhibition factor than a bond formed by a binding substance without being mixed with the test substance.