Engineered pH-Sensitive Protein G/IgG Interaction

Jha, Ramesh K.; Yankey, Allison; Shabazz, Kalifa; Naranjo, Leslie; Shin, Sang-Min; Velappan, Nileena; Bradbury, Andrew M.; Strauss, Charlie M.

doi:10.1021/acschembio.0c00943

DOE OSTI · 1830582

Engineered pH-Sensitive Protein G/IgG Interaction

Jha, Ramesh K.·Yankey, Allison·Shabazz, Kalifa·Naranjo, Leslie·Shin, Sang-Min·Velappan, Nileena·Bradbury, Andrew M.·Strauss, Charlie M.

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Abstract

While natural protein–protein interactions have evolved to be induced by complex stimuli, rational design of interactions that can be switched-on-demand still remain challenging in the protein design world. Here, we demonstrate that a computationally redesigned natural interface for improved binding affinity could further be mutated to adopt a pH switchable interaction. The redesigned interface of Protein G/human IgG Fc domain (referred to as PrG/hIgG), when incorporated with histidine and glutamic acid on PrG (PrG-EHHE), showed a switch in binding affinity by 50-fold when the pH was altered from mild acidic to mild basic. The wild-type (WT) interface showed a negligible switch. The overall binding affinity under mild acidic pH for PrG-EHHE outperformed the wild-type PrG (PrG-WT) interaction. Overall, we find that the new reagent PrG-EHHE can be revolutionary in IgG purification, since the standard method of using an extreme acidic pH for elution can be circumvented.

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59 BASIC BIOLOGICAL SCIENCES Biological science fungi genetics monomers pH peptides and proteins protein design, IgG, antibody purification, pH switch

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Jha, Ramesh K., Yankey, Allison, Shabazz, Kalifa, Naranjo, Leslie, Shin, Sang-Min, Velappan, Nileena, Bradbury, Andrew M., Strauss, Charlie M.. 2021-06-21. Engineered pH-Sensitive Protein G/IgG Interaction. https://doi.org/10.1021/acschembio.0c00943

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