5UBX

Crystal structure of a mutant mIgG2b Fc heterodimer in complex with Protein A peptide analog Z34C

Summary for 5UBX

• Entry DOI: 10.2210/pdb5ubx/pdb
• Descriptor: Ig gamma-2B chain C region, Peptide analog of B-domain from Protein A - Z34C, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (6 entities in total)
• Functional Keywords: protein a, fc complex, b-domain, z-domain, immunoglobulin fold, immune system
• Biological source: Mus musculus (Mouse); More
• Cellular location: Isoform 1: Cell membrane ; Single-pass membrane protein . Isoform 2: Secreted: P01867 P01867
• Total number of polymer chains: 3
• Total formula weight: 59278.68

Authors

Armstrong, A.A.,Zwolak, A.,Gilliland, G.L. (deposition date: 2016-12-21, release date: 2017-09-20, Last modification date: 2024-11-20)

Primary citation

Zwolak, A.,Armstrong, A.A.,Tam, S.H.,Pardinas, J.R.,Goulet, D.R.,Zheng, S.,Brosnan, K.,Emmell, E.,Luo, J.,Gilliland, G.L.,Chiu, M.L.
Modulation of protein A binding allows single-step purification of mouse bispecific antibodies that retain FcRn binding.
MAbs, 9:1306-1316, 2017

PubMed Abstract: The increased number of bispecific antibodies (BsAb) under therapeutic development has resulted in a need for mouse surrogate BsAbs. Here, we describe a one-step method for generating highly pure mouse BsAbs suitable for in vitro and in vivo studies. We identify two mutations in the mouse IgG2a and IgG2b Fc region: one that eliminates protein A binding and one that enhances protein A binding by 8-fold. We show that BsAbs harboring these mutations can be purified from the residual parental monoclonal antibodies in one step using protein A affinity chromatography. The structural basis for the effects of these mutations was analyzed by X-ray crystallography. While the mutation that disrupted protein A binding also inhibited FcRn interaction, a bispecific mutant in which one subunit retained the ability to bind protein A could still interact with FcRn. Pharmacokinetic analysis of the serum half-lives of the mutants showed that the mutant BsAb had a serum half-life comparable to a wild-type Ab. The results describe a rapid method for generating panels of mouse BsAbs that could be used in mouse studies.

PubMed: 28898162
DOI: 10.1080/19420862.2017.1375639

Experimental method

X-RAY DIFFRACTION (2.7 Å)