7PKL

Mechanistic understanding of antibody masking with anti-idiotypic antibody fragments

Summary for 7PKL

• Entry DOI: 10.2210/pdb7pkl/pdb
• Descriptor: trastuzumab Heavy Chain, trastuzumab Light Chain VHH fusion, SULFATE ION, ... (4 entities in total)
• Functional Keywords: trastuzumab, vhh, nanobody, dab, immune system
• Biological source: Homo sapiens; More
• Total number of polymer chains: 2
• Total formula weight: 64236.83

Authors

Hargreaves, D. (deposition date: 2021-08-25, release date: 2022-09-07, Last modification date: 2024-10-16)

Primary citation

Orozco, C.T.,Bersellini, M.,Irving, L.M.,Howard, W.W.,Hargreaves, D.,Devine, P.W.A.,Siouve, E.,Browne, G.J.,Bond, N.J.,Phillips, J.J.,Ravn, P.,Jackson, S.E.
Mechanistic insights into the rational design of masked antibodies.
Mabs, 14:2095701-2095701,

PubMed Abstract: Although monoclonal antibodies have greatly improved cancer therapy, they can trigger side effects due to on-target, off-tumor toxicity. Over the past decade, strategies have emerged to successfully mask the antigen-binding site of antibodies, such that they are only activated at the relevant site, for example, after proteolytic cleavage. However, the methods for designing an ideal affinity-based mask and what parameters are important are not yet well understood. Here, we undertook mechanistic studies using three masks with different properties and identified four critical factors: binding site and affinity, as well as association and dissociation rate constants, which also played an important role. HDX-MS was used to identify the location of binding sites on the antibody, which were subsequently validated by obtaining a high-resolution crystal structure for one of the mask-antibody complexes. These findings will inform future designs of optimal affinity-based masks for antibodies and other therapeutic proteins.

PubMed: 35799328
DOI: 10.1080/19420862.2022.2095701

Experimental method

X-RAY DIFFRACTION (2.35 Å)