Download MendeleyUsing phage display for rational engineering of a higher affinity humanized 3' phosphohistidine-specific antibody.
Martyn, G.D., Kalagiri, R., Veggiani, G., Stanfield, R.L., Choudhuri, I., Sala, M., Meisenhelder, J., Chen, C., Biswas, A., Levy, R.M., Lyumkis, D., Wilson, I.A., Hunter, T., Sidhu, S.S.(2024) bioRxiv
- PubMed: 39574610
- DOI: https://doi.org/10.1101/2024.11.04.621849
- Primary Citation of Related Structures:
8UHH, 8UHJ, 8UHN, 8UHP, 8UHS, 8UHT, 8UIG, 8UIH, 8UIO, 8UIT, 8UJI - PubMed Abstract:
Histidine phosphorylation (pHis) is a non-canonical post-translational modification (PTM) that is historically understudied due to a lack of robust reagents that are required for its investigation, such as high affinity pHis-specific antibodies. Engineering pHis-specific antibodies is very challenging due to the labile nature of the phosphoramidate (P-N) bond and the stringent requirements for selective recognition of the two isoforms, 1-phosphohistidine (1-pHis) and 3-phosphohistidine (3-pHis). Here, we present a strategy for in vitro engineering of antibodies for detection of native 3-pHis targets. Specifically, we humanized the rabbit SC44-8 anti-3-pTza (a stable 3-pHis mimetic) mAb into a scaffold (herein referred to as hSC44) that was suitable for phage display. We then constructed six unique Fab phage-displayed libraries using the hSC44 scaffold and selected high affinity 3-pHis binders. Our selection strategy was carefully designed to enrich antibodies that bound 3-pHis with high affinity and had specificity for 3-pHis versus 3-pTza. hSC44.20N32F L , the best engineered antibody, has an ~10-fold higher affinity for 3-pHis than the parental hSC44. Eleven new Fab structures, including the first reported antibody-pHis peptide structures were solved by X-ray crystallography. Structural and quantum mechanical calculations provided molecular insights into 3-pHis and 3-pTza discrimination by different hSC44 variants and their affinity increase obtained through in vitro engineering. Furthermore, we demonstrate the utility of these newly developed high-affinity 3-pHis-specific antibodies for recognition of pHis proteins in mammalian cells by immunoblotting and immunofluorescence staining. Overall, our work describes a general method for engineering PTM-specific antibodies and provides a set of novel antibodies for further investigations of the role of 3-pHis in cell biology.
- School of Pharmacy, University of Waterloo, 10 Victoria St A, Kitchener, ON, N2G 1C5, Canada.
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