This model represents the antigen-binding fragment (Fab) of 1G01, a human monoclonal antibody that inhibits neuraminidase from diverse influenza A and B viruses. The Fab corresponds to one antigen-binding arm of an antibody and contains a light chain and part of a heavy chain. The heavy chain is in dark blue, and the light chain is a lighter shade of blue.

A prominent, 21-amino-acid loop in the heavy chain, called CDR H3, extends into neuraminidase’s catalytic pocket. Arg100 is colored yellow to highlight the tip of this loop. By occupying this site, 1G01 blocks the enzyme’s ability to remove terminal sialic acids from carbohydrate chains—a process that helps newly formed influenza viruses detach from infected cells and spread.

This model was created from PDB 6Q23 using ChimeraX 1.12.