Binding molecules and methods of use thereof

An isolated binding molecule of the formula (II):

• wherein
• at least one Z is Ab, wherein Ab is a polypeptide comprising at least one antigen binding site;
• L is an independently selected linker moiety for each occurrence or B when adjacent to a Z which is Ab;
• B is a bridging moiety, wherein B is linked to Ab through a carboxylate or amino linkage;
• R is selected independently for each occurrence from the group consisting of alkyl, alkenyl, alkynyl, acyl, and hydrogen;
• Z is an independently selected drug moiety, affinity moiety, tag moiety, pharmokinetic moiety, hydrogen, amino acid side chain moiety, or Ab for each occurrence;
• w and y are each independently selected for each occurrence from the group consisting of 1, 2, 3, 4, and 5;
• b and d are each independently selected for each occurrence from integers greater than 1, and pharmaceutically acceptable salts, esters, and prodrugs thereof.