Selenocysteine mediated hybrid antibody molecules

Abstract

The invention provides methods and compositions employing hybrid molecules of a synthetic molecule and antibody or antibody fragment comprising a selenocysteine residue, wherein the synthetic molecule is covalently linked to the antibody or antibody fragment at the selenocysteine residue. The invention also provides a composition comprising a hybrid molecule as described above and a pharmaceutically acceptable carrier. The invention further provides for methods of making the hybrid molecules, and methods of using the hybrid molecule described above to inhibit cell surface receptor binding.

1 . A composition comprising
 (a) a hybrid molecule comprising a synthetic molecule and an antibody or antibody fragment selected from the group consisting of Fc, F(ab′)2, Fab, scFv, IgGΔCH2, scFv2CH3, scFv4, scFv3, scFv2, dsFv, and scFv-Fc, wherein the antibody or antibody fragment comprises at least one selenocysteine residue, wherein the at least one selenocysteine residue is located within 300 amino acids of a C-terminus of the antibody or antibody fragment in a constant domain of the antibody or antibody fragment, and wherein the synthetic molecule is covalently linked to the antibody or antibody fragment at the selenocysteine residue, and   (b) a pharmaceutically acceptable carrier.   
     
     
         2 . The composition of  claim 1 , wherein the antibody is selected from the group consisting of IgA, IgD, IgE, IgG, and IgM. 
     
     
         3 . The composition of  claim 1 , wherein the antibody is rituximab. 
     
     
         4 - 5 . (canceled) 
     
     
         6 . The composition of  claim 1 , wherein the antibody fragment is an Fc domain. 
     
     
         7 . The composition of  claim 1 , wherein the antibody fragment is an Fab domain. 
     
     
         8 . The composition of  claim 1 , wherein the antibody or antibody fragment comprises only one selenocysteine residue. 
     
     
         9 . The composition of  claim 1 , wherein the antibody or antibody fragment comprises more than one selenocysteine residue. 
     
     
         10 . (canceled) 
     
     
         11 . The composition of  claim 1 , wherein the at least one selenocysteine residue is located within 150 amino acids of the C-terminus of the antibody or antibody fragment in a constant domain of the antibody or antibody fragment. 
     
     
         12 . The composition of  claim 1 , wherein the at least one selenocysteine residue is located within 50 amino acids of the C-terminus of the antibody or antibody fragment in a constant domain of the antibody or antibody fragment. 
     
     
         13 . The composition of  claim 1 , wherein the antibody or antibody fragment is produced using a eukaryotic expression system. 
     
     
         14 . The composition of  claim 13 , wherein the antibody or antibody fragment is produced using a mammalian expression system. 
     
     
         15 . The composition of  claim 1 , wherein the synthetic molecule comprises an iodoacetamide, bromoacetamide, chloroacetamide, maleimide, or acrylamide moiety. 
     
     
         16 . The composition of  claim 1 , wherein the synthetic molecule comprises a binding moiety for an integrin selected from the group consisting of α 4 β 1 , α 4 β 7 , α v β 3 , α v β 5 , α V β 6 , α 5 β 1 , and α IIB β 3 . 
     
     
         17 . The composition of  claim 1 , wherein the synthetic molecule comprises a binding moiety for a receptor selected from the group consisting of CCR5, LHRH, CXCR4, TPO, folate, endothelin, and vitamin B12. 
     
     
         18 . The composition of  claim 16 , wherein the synthetic molecule comprises both an α 4 β 1  and an α 4 β 7  integrin binding moiety. 
     
     
         19 . The composition of  claim 1 , wherein the synthetic molecule comprises a biotin moiety. 
     
     
         20 . The composition of  claim 1 , wherein the synthetic molecule comprises an α4β1 integrin binding moiety, a biotin moiety, and a maleimide moiety. 
     
     
         21 . The composition of  claim 1 , wherein the synthetic molecule comprises a radioisotope. 
     
     
         22 . The composition of  claim 1 , wherein the synthetic molecule comprises a cytotoxic agent. 
     
     
         23 . The composition of  claim 22 , wherein the cytotoxic agent is selected from the group consisting of doxorubicin, calicheamicin, maytansinoid, and auristatin. 
     
     
         24 . The composition of  claim 1 , wherein the synthetic molecule is covalently linked to the selenocysteine residue by a polyethylene glycol (PEG) linker. 
     
     
         25 . The composition of  claim 24 , wherein the PEG linker comprises poly(ethylene glycol)-succinamide-lysine-lysine-maleimide. 
     
     
         26 - 65 . (canceled) 
     
     
         66 . The composition of  claim 1 , wherein the at least one selenocysteine residue is cotranslationally incorporated at a UGA stop codon of the antibody or antibody fragment that was recoded from termination to selenocysteine insertion.