5JIK

Crystal structure of HER2 binding IgG1-Fc (Fcab H10-03-6)

Summary for 5JIK

• Entry DOI: 10.2210/pdb5jik/pdb
• Related: 5JIH 5JII
• Descriptor: Ig gamma-1 chain C region, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-6)-[alpha-D-mannopyranose-(1-3)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (4 entities in total)
• Functional Keywords: immune system, antibody engineering, immunoglobulin g1, fc fragment, glycosylations, ch3 domain, fcab, her2, erbb-2
• Biological source: Homo sapiens (Human)
• Cellular location: Secreted : P01857
• Total number of polymer chains: 2
• Total formula weight: 53306.96

Authors

Humm, A.,Lobner, E.,Mlynek, G.,Obinger, C.,Djinovic-Carugo, K. (deposition date: 2016-04-22, release date: 2017-04-12, Last modification date: 2024-11-06)

Primary citation

Lobner, E.,Humm, A.S.,Goritzer, K.,Mlynek, G.,Puchinger, M.G.,Hasenhindl, C.,Ruker, F.,Traxlmayr, M.W.,Djinovic-Carugo, K.,Obinger, C.
Fcab-HER2 Interaction: a Menage a Trois. Lessons from X-Ray and Solution Studies.
Structure, 25:878-889.e5, 2017

PubMed Abstract: The crystallizable fragment (Fc) of the immunoglobulin class G (IgG) is an attractive scaffold for the design of novel therapeutics. Upon engineering the C-terminal loops in the CH3 domains, Fcabs (Fc domain with antigen-binding sites) can be designed. We present the first crystal structures of Fcabs, i.e., of the HER2-binding clone H10-03-6 having the AB and EF loop engineered and the stabilized version STAB19 derived by directed evolution. Comparison with the crystal structure of the Fc wild-type protein reveals conservation of the overall domain structures but significant differences in EF-loop conformations. Furthermore, we present the first Fcab-antigen complex structures demonstrating the interaction between the engineered Fcab loops with domain IV of HER2. The crystal structures of the STAB19-HER2 and H10-03-6-HER2 complexes together with analyses by isothermal titration calorimetry, SEC-MALS, and fluorescence correlation spectroscopy show that one homodimeric Fcab binds two HER2 molecules following a negative cooperative binding behavior.

PubMed: 28528777
DOI: 10.1016/j.str.2017.04.014

Experimental method

X-RAY DIFFRACTION (1.82 Å)