3EO9

Crystal structure the Fab fragment of Efalizumab

Summary for 3EO9

• Entry DOI: 10.2210/pdb3eo9/pdb
• Related: 3EOA 3EOB
• Descriptor: Efalizumab Fab fragment, light chain, Efalizumab Fab fragment, heavy chain (3 entities in total)
• Functional Keywords: efalizumab, fab, antibody, immune system
• Biological source: Homo sapiens; More
• Total number of polymer chains: 2
• Total formula weight: 47058.57

Authors

Li, S.,Ding, J. (deposition date: 2008-09-26, release date: 2009-04-14, Last modification date: 2024-10-09)

Primary citation

Li, S.,Wang, H.,Peng, B.,Zhang, M.,Zhang, D.,Hou, S.,Guo, Y.,Ding, J.
Efalizumab binding to the LFA-1 alphaL I domain blocks ICAM-1 binding via steric hindrance.
Proc.Natl.Acad.Sci.USA, 106:4349-4354, 2009

PubMed Abstract: Lymphocyte function-associated antigen 1 (LFA-1) plays important roles in immune cell adhesion, trafficking, and activation and is a therapeutic target for the treatment of multiple autoimmune diseases. Efalizumab is one of the most efficacious antibody drugs for treating psoriasis, a very common skin disease, through inhibition of the binding of LFA-1 to the ligand intercellular adhesion molecule 1 (ICAM-1). We report here the crystal structures of the Efalizumab Fab alone and in complex with the LFA-1 alpha(L) I domain, which reveal the molecular mechanism of inhibition of LFA-1 by Efalizumab. The Fab binds with an epitope on the inserted (I) domain that is distinct from the ligand-binding site. Efalizumab binding blocks the binding of LFA-1 to ICAM-1 via steric hindrance between its light chain and ICAM-1 domain 2 and thus inhibits the activities of LFA-1. These results have important implications for the development of improved antibodies and new therapeutic strategies for the treatment of autoimmune diseases.

PubMed: 19258452
DOI: 10.1073/pnas.0810844106

Experimental method

X-RAY DIFFRACTION (1.8 Å)