7UT3

Crystal structure of complex of Fab, G10C with GalNAc-pNP

Summary for 7UT3

• Entry DOI: 10.2210/pdb7ut3/pdb
• Descriptor: Fab protein heavy chain, G10C Light chain, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL, ... (5 entities in total)
• Functional Keywords: fab, galnac-pnp, immune system
• Biological source: Mus musculus (mouse); More
• Total number of polymer chains: 2
• Total formula weight: 47375.81

Authors

Li, M.,Wlodawer, A. (deposition date: 2022-04-26, release date: 2022-09-21, Last modification date: 2024-10-23)

Primary citation

Xia, L.,Bellomo, T.R.,Gibadullin, R.,Congdon, M.D.,Edmondson, E.F.,Li, M.,Wlodawer, A.,Li, C.,Temme, J.S.,Patel, P.,Butcher, D.,Gildersleeve, J.C.
Development of a GalNAc-Tyrosine-Specific Monoclonal Antibody and Detection of Tyrosine O -GalNAcylation in Numerous Human Tissues and Cell Lines.
J.Am.Chem.Soc., 144:16410-16422, 2022

PubMed Abstract: Glycosylation is a vital post-translational modification involved in a range of biological processes including protein folding, signaling, and cell-cell interactions. In 2011, a new type of -linked glycosylation was discovered, wherein the side-chain oxygen of tyrosine is modified with a GalNAc residue (GalNAc-Tyr). At present, very little is known about GalNAc-Tyr prevalence, function, or biosynthesis. Herein, we describe the design and synthesis of a GalNAc-Tyr-derived hapten and its use in generating a GalNAc-Tyr selective monoclonal antibody. The antibody, G10C, has an unusually high affinity (app = 100 pM) and excellent selectivity for GalNAc-Tyr. We also obtained a crystal structure of the G10C Fab region in complex with 4-nitrophenyl--acetyl-α-d-galactosaminide (a small molecule mimic of GalNAc-Tyr) providing insights into the structural basis for high affinity and selectivity. Using this antibody, we discovered that GalNAc-Tyr is widely expressed in most human tissues, indicating that it is a ubiquitous and underappreciated post-translational modification. Localization to specific cell types and organ substructures within those tissues indicates that GalNAc-Tyr is likely regulated in a cell-specific manner. GalNAc-Tyr was also observed in a variety of cell lines and primary cells but was only present on the external cell surface in certain cancer cell lines, suggesting that GalNAc-Tyr localization may be altered in cancer cells. Collectively, the results shed new light on this under-studied form of glycosylation and provide access to new tools that will enable expanded biochemical and clinical investigations.

PubMed: 36054098
DOI: 10.1021/jacs.2c04477

Experimental method

X-RAY DIFFRACTION (3 Å)