Cow's milk protein is a whole, undigested, multi-dimensional protein. Since proteins exist in an aqueous (i.e., watery) environment, reactivity to whole proteins is predominantly to the outer, water-soluble portions of the proteins. In contrast, whey and casein are 2-dimensional peptides created when whole cow's milk proteins are digested (i.e., denatured and cleaved into fragments). Antibodies to a whole, multi-dimensional protein will not recognize or bind small peptide fragments, even if those peptides are found in that whole protein, and vice versa.
See the Peptide vs Whole Protein One-Pager for more information.
