immunoglobulin g antibody molecule. computer model showing the secondary structure of an immunoglobulin g (igg) molecule. this is the most abundant immunoglobulin antibody and is found in all body fluids. - secondary protein structure stock pictures, royalty-free photos & imagesImmunoglobulin G antibody molecule. Computer model showing the secondary structure of an immunoglobulin G (IgG) molecule. This is the most abundant immunoglobulin antibody and is found in all body fluids.