[47] Preparation and properties of anti-biotin antibodies

This chapter discusses the preparation and properties of anti-biotin antibodies. The chapter produces a high-affinity monoclonal antibody to biotin and compares the binding properties of the monoclonal anti-biotin with that of streptavidin in the development of noncompetitive immunoassays for polypeptide hormones and haptens. The VH and the VL cDNA of this antibody are sequenced and cloned. A comparative analysis of the VH sequence of the anti-biotin antibody with those of avidin and streptavidin reveals a similarity in the CDR2 and CDR3 regions of the antibody with known biotin-binding motifs in two of the homologous stretches of avidin and streptavidin. The VL sequence shows no similarity to such stretches of avidin or streptavidin. The second homologous stretch of avidin and streptavidin contains the sequence XXXYXT(S)XX, and the CDR2 region of the heavy chain of the antibody contains RTNYNSGL. Similarly, the fourth homologous stretch of avidin and streptavidin contains the sequence XXTXF(W)XG and the CDR3 region of the antibody heavy chain contains HTNWDG. These results seem to indicate a similar pattern in the sequences that may dictate the quality of biotin binding.