Abstract: A variant of a polypeptide comprising a human IgG Fc region is described, which variant comprises an amino acid substitution at one or more of amino acid positions 270, 322, 326, 327, 329, 331, 333 or 334 of the human IgG Fc region. Such variants display altered effector function. For example, C1q binding and/or complement dependent cytotoxicity (CDC) activity may be altered in the variant polypeptide.

Abstract: Transition state analogs are described which may be used to elicit antibodies that catalyze the conversion of asparagine to aspartic acid. Synthetic schemes are disclosed for making the transition state analogs which can than be attached to a carrier molecule to form an immunoconjugate. Immunoconjugates can be administered to an animal for the purpose of raising antibodies. Antibodies can in turn be used in pharmaceutical compositions which can be given to patients as part of a method of treating various conditions, particularly cancer.