Antibody binding reports spatial heterogeneities in cell membrane organization

• Published in: Nature communications Vol. 14; no. 1; p. 2884
• Main Authors: Arnold, Daniel P., Xu, Yaxin, Takatori, Sho C.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20.05.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/57/2270; 631/57/2282; 639/766/747; Antibodies, Monoclonal - metabolism; Antigens; Binding; Cell Membrane - metabolism; Cell membranes; Cell signaling; Glycolipids; Glycoproteins; Glycoproteins - metabolism; Humanities and Social Sciences; Humans; Immunoglobulin G; Macromolecular Substances - chemistry; Macromolecules; Membrane glycoproteins; Membrane proteins; Membrane Proteins - metabolism; Membranes; Monoclonal antibodies; multidisciplinary; Phagocytosis; Proteins; Science; Science (multidisciplinary); Spatial discrimination; Spatial resolution
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-38525-2

The spatial organization of cell membrane glycoproteins and glycolipids is critical for mediating the binding of ligands, receptors, and macromolecules on the plasma membrane. However, we currently do not have the methods to quantify the spatial heterogeneities of macromolecular crowding on live cell surfaces. In this work, we combine experiment and simulation to report crowding heterogeneities on reconstituted membranes and live cell membranes with nanometer spatial resolution. By quantifying the effective binding affinity of IgG monoclonal antibodies to engineered antigen sensors, we discover sharp gradients in crowding within a few nanometers of the crowded membrane surface. Our measurements on human cancer cells support the hypothesis that raft-like membrane domains exclude bulky membrane proteins and glycoproteins. Our facile and high-throughput method to quantify spatial crowding heterogeneities on live cell membranes may facilitate monoclonal antibody design and provide a mechanistic understanding of plasma membrane biophysical organization. The organization of proteins and sugars on the cell membrane is crucial for cell signaling and function. Here, authors develop molecular probes and simulations to characterize the spatial organization of macromoleucles on live cell membranes.