A Generic Approach to Engineer Antibody pH-Switches Using Combinatorial Histidine Scanning Libraries and Yeast Display

Schroter C, et al., 7(1):138-51, MAbs, 2015

This is a strategy to develop antibodies with reversible pH-sensitive antigen binding capabilities. Combinatorial histidine substitution libraries made out of VH and VL portions of adalimumab was used in this proof of concept experiment. Adalimumab is a human IgG antibody that targets tumor necrosis factor (TNF). The authors isolated VH and VL variants with high affinity at pH 7.4 and a considerable increase in antigen release at pH 6 after 3-rounds of yeast-display screening. The pH sensitive antigen binding was confirmed using an Octet RED system equipped with anti-human Fc (AHC) biosensors. These biosensors captured the antibody allowing concentration dependent titrations with rhTNF. Furthermore, the authors used the Octet platform to provide evidence of reversible binding at varying pH conditions.

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