antibody molecule

Ever wondered what the antibodies that help protect you from infection look like?

This is a model of one type (class) of antibody, called IgG (immunoglobulin G) It's a symmetrical structure consisting of two "heavy" chains, which give the Y shape in the model, and two additional chains, the "light" chains, which are associated with each of the arms of the Y. This model is derived from an x-ray crystallographic structure of IgG1, which is available from the protein databank (PDB). The nominal molecular surface of the IgG has been skinned, so all the various individual molecules get fused into a continuous surface. Unless my quick calculation is off, the model, if left as is, is approximately 6.2 million times bigger than an actual IgG.
The two identical arms (each being partly made of a heavy chain and a light chain, bind to the antibodies target "antigen" - so a single IgG can bind to two identical target molecules. Search for antibody on the web, if you are curious abou