comment "Description: A protein reference is a grouping of several protein entities that are encoded by the same genetic sequence. Members can differ in any combination of cellular location, sequence features and bound partners.
Rationale: Protein molecules, encoded by the same genetic sequence can be present in (combinatorially many) different states, as a result of post translational modifications and non-covalent bonds. Each state, chemically, is a different pool of molecules. They are, however, related to each other because:
They all share the same "base" genetic sequence.
They can only be converted to each other but not to any other protein
Comments:Most Protein databases, including UniProt would map one to one with ProteinReferences in BioPAX." (string)