| abstract |
The present invention features inter alia altered binding polypeptides having engineered cysteine residues or analogs thereof at a predetermined site within, for example, a constant region domain or a portion thereof. The engineered cysteine residues or analogs thereof provide sites for conjugating effector moieties (e.g. diagnostic or therapeutic agents) that impart novel functionality to the binding polypeptide, preferably without interfering with a desirable property (e.g. an Fc-mediated effector function). The invention includes methods for the rational design of such altered polypeptides, as well as methods for modifying (ie. conjugating) the altered polypeptides with desirable effector moieties. Particular modified binding polypeptides (ie. immunoconjugates) of altered binding polypeptides and methods for utilizing such modified binding polypeptides as protein-based therapeutics are also provided. |