The present invention relates to: a polypeptide that includes an antigen-binding domain and a carrying section having an inhibitory domain for inhibiting the antigen-binding activity of the antigen-binding domain, said polypeptide having a half-life longer than that of the antigen-binding domain when existing alone； a production method and a screening method for said polypeptide； a pharmaceutical composition containing said polypeptide； a production method and a screening method for a single-domain antibody, the antigen-binding activity of which is inhibited by being associated with a specific VL/VH/VHH； and a library of fused polypeptides including a single-domain antibody, the antigen-binding activity of which is inhibited by being associated with a specific VL/VH/VHH.本發明係關於含有抗原結合域、及具抑制抗原結合域之抗原結合活性之抑制域之運輸部分且比起單獨存在之抗原結合域有較長半衰期之多胜肽、該多胜肽之製造方法及篩選方法、含該多胜肽之醫藥組合物、藉由和特定之VL/VH/VHH締合而抗原結合活性受抑制之單域抗體之製造方法及篩選方法、及藉由和特定之VL/VH/VHH締合而抗原結合活性受抑制之含單域抗體之融合多胜肽之資料庫。
