Disclosed are compositions and methods related to variable lymphocyte receptors (VLRs). More particularly, disclosed are a variety of antigen specific polypeptides, including soluble, monoclonal, and multivalent forms, as well as methods of using the polypeptides, antibodies that bind the antigen specific polypeptides, and nucleic acids, vectors and expression systems that encode the polypeptides. Antigen specific polypeptides that selectively bind pathogens, like anthrax, and carbohydrates, like blood group determinants, are specifically disclosed.
