Modulation of protein A binding allows single-step purification of mouse bispecific antibodies that retain FcRn binding.

ABSTRACT: The increased number of bispecific antibodies (BsAb) under therapeutic development has resulted in a need for mouse surrogate BsAbs. Here, we describe a one-step method for generating highly pure mouse BsAbs suitable for in vitro and in vivo studies. We identify two mutations in the mouse IgG2a and IgG2b Fc region: one that eliminates protein A binding and one that enhances protein A binding by 8-fold. We show that BsAbs harboring these mutations can be purified from the residual parental monoclonal antibodies in one step using protein A affinity chromatography. The structural basis for the effects of these mutations was analyzed by X-ray crystallography. While the mutation that disrupted protein A binding also inhibited FcRn interaction, a bispecific mutant in which one subunit retained t

SUBMITTER: Zwolak A 

PROVIDER: S-EPMC5680793 | biostudies-literature | 2017 Nov/Dec

REPOSITORIES: biostudies-literature