CONJUGATION OF POLYPEPTIDES TO PROTEIN CARRIERS A. Functional Groups--The polypeptides described herein may be coupled to protein or high molecular weight (macromolecular) polymeric carriers (or substrates) through several types of functional groups on the antigen, e.g. (a) ?? or ??-amino groups, (b) ??, ??, or ??-carboxyl groups, (c) thiol (--SH) groups, (d) aromatic rings (e.g., Tyr, His) B. Spe