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Antibody-Antigen Complex Structure by X-ray Crystallography

Three-dimensional X-ray crystallographic structures of antigen-antibody complexes are essential for elucidating the details of epitope-paratope interactions and for optimizing the binding interactions within a complex. A structural knowledge will be a strong contributor to the acceleration of any therapeutics program and will provide clear and indisputable data for patent applications. We at SARomics Biostructures have gathered extensive experience in the work with antibody:antigen complexes, which includes biophysical characterization in solution, crystallization and X-ray structure determination (see our case study below). Our crystallography services platform includes all necessary equipment and tools for handling projects of this type.

Please, also view the details of our
higher order structure comparability assessment services.

X-ray structure of an antigen-antibody complex: Fab-LukGH

LukGH (LukAB) is a potent leukocidin of Staphylococcus aureus that lyses human phagocytic cells and is thought to contribute to immune evasion. Unlike the other bi-component leukocidins of S. aureus, LukGH forms a heterodimer before binding to its receptor, CD11b expressed on professional phagocytic cells, and displays significant sequence variation.
In this project we performed X-ray crystallography analysis of the complex between the LukGH dimer and the antigen-binding fragment of a very potent mAb (PDB code 5K59). The three-dimensional structure of the complex clearly indicated that the epitope is located in the predicted cell binding region (rim domain) of LukGH.

Details can be found in the publication (open access):
Badarau A, Rouha H, Malafa S, Battles MB, Walker L, Nielson N, Dolezilkova I, Teubenbacher A, Banerjee S, Maierhofer B, Weber S, Stulik L, Logan DT, Welin M, Mirkina I, Pleban C, Zauner G, Gross K, Jägerhofer M, Magyarics Z & Nagy E (2016). Context matters: The importance of dimerization-induced conformation of the LukGH leukocidin of Staphylococcus aureus for the generation of neutralizing antibodies. MAbs. 8, 1347-1360.

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