Higher Order Structure of Antibodies & Comparability Analysis

SARomics Biostructures' team has extensive experience in X-ray and NMR spectroscopic analysis of antibody and antibody-antigen complex structures. Our services include structural characterization and comparability studies of biosimilars' higher order structure (HOS). We use a combination of X-ray crystallography and NMR spectroscopy for comparability analysis of HOS. All our studies include biophysical characterization of the state of antibodies and biosimilars in solution.

The value of the insights provided by the three-dimensional structure cannot be overestimated. Structural information can be used for:
  • Epitope definition to file stronger IP
  • Understanding the mode of action
  • Structure-based antibody engineering: affinity maturation, humanization, ADC, etc.
  • Structural characterization of protein drugs for regulatory purposes
  • Validation of higher order structures of biosimilars and comparability analysis

X-ray crystallography services platform is equipped to handle projects of all types, including challenging projects. To discuss your project, please do not hesitate to contact us.

Case studies
The pdf below provides a short company introduction and shows several case studies involving antibody-antigen complex structures. They were published recently in leading journals such as PNAS, Nat Comm, Cell Reports, iScience, Cancer Ther, Blood Ad, and Structure. The determined structures include:

  • Bispecific anti-Met/EpCAM mAb MM-131 in complex with its antigens (Merrimack Pharmaceuticals).
  • ALPN-202 (An engineered CD80 variant fusion therapeutic) in complex with PD-L1 (Alpine Immune Sciences).
  • SRF388 Fab in complex IL-27 (Surface Oncology Inc.),
  • ActRIIB-Alk4-Fc in complex with activin A and anti-ActRIIB Fab (Acceleron Pharma).
  • ALG.APV-527 (Fab1618) in complex with 4-1BB (CD137) (Alligator Bioscience AB).
  • Glenzocimab Fab in complex with platelet glycoprotein VI (Acticor Biotech),
  • DutaFab (Roche) in complex with its antigens PDGF and VEGFA.
  • Dusquetide in complex with p62 (SQSTM1) ZZ domain (Soligenix, Inc.).

publications page provides additional examples.
For an overview of our services, please, download the white paper below.

On the image: Martin Welin, PhD, Senior Scientist, Team Leader, Protein Crystallography.

Higher order structure analysis & characterization of Biosimilars

Testing, analysis, and validation of higher order structures of biosimilars are critical to developing products that adhere to patient safety principles. SARomics Biostructures offers a multidisciplinary approach for the best possible comparability assessment and analysis of HOS at atomic resolution. By combining NMR spectroscopy and X-ray crystallography, we can provide global structural information and detailed atomic position analysis, which will detect any differences in the structures of the antibodies. Details can be found on our NMR services page.

Our biosimilar characterization and analysis are based on advances in NMR spectroscopy that have made it possible to acquire a unique fingerprint representation of the 3D conformation of large, complex molecules like biologics without expensive isotope labeling. By directly matching the NMR fingerprint of a given protein to its high-resolution 3D structure, determined, e.g., by X-ray crystallography, or to a fingerprint of another protein batch or a biosimilar, we can rapidly assess and analyze comparability and show that the molecules, for example, a biosimilar and its originator, or different batches or alternative preparations of the same biologic, have identical HOS.

Recent publications

Skladanowska K, Bloch Y, Strand J, White K, Hua J, Aldridge D, Welin M, Logan DT, Soete A, Merceron R, Murphy C, Provost M, Bazan JF, Hunter C, Hill J & Savvides SN. Structural basis of activation and antagonism of receptor signaling mediated by interleukin-27.
Cell Reports, 41, 111490. doi:https://doi.org/10.1016/j.celrep.2022.111490

Interleukin-27 (IL-27) uniquely assembles p28 and EBI3 subunits to a heterodimeric cytokine that signals via IL-27Rα and gp130. To provide the structural framework for receptor activation by IL-27 and its emerging therapeutic targeting, the crystal structures of mouse IL-27 in complex with IL-27Rα and human IL-27 in complex with SRF388, a monoclonal antibody undergoing clinical trials with oncology indications, were determined.

For the complete publication list, please visit our publications page.

For related services please follow the respective link

X-ray crystallographic services

X-ray crystallography services

Protein NMR spectroscopy services

Protein NMR spectroscopy services

In silico protein optimization services

Structure-based design of biological drugs