Modified ciliary neurotrophic factors

Abstract

Modified ciliary neurotrophic factors and methods for their production and therapeutic use. Also described is a method of screening for novel therapeutic proteins by determining altered electrophoretic binding properties.

I claim:  
     
         1 . Human ciliary neurotrophic factor having the modification Gln63→Arg.  
     
     
         2 . Modified ciliary neurotrophic factor according to  claim 1 , further having the modification Trp64→Ala.  
     
     
         3 . Modified ciliary neurotrophic factor according to  claim 1 , further having the modification Cys17→Ala and a deletion of the terminal 13 amino acid residues.  
     
     
         4 . Modified ciliary neurotrophic factor according to  claim 1 , further having a deletion of the terminal 13 amino acid residues.  
     
     
         5 . The modified ciliary neurotrophic factor of  claim 2 , designated RG 242.  
     
     
         6 . The modified ciliary neurotrophic factor of  claim 3 , designated RG 297.  
     
     
         7 . The modified ciliary neurotrophic factor of  claim 4 , designated RG 290.  
     
     
         8 . An isolated and purified nucleic acid molecule encoding the modified human CNTF of  claim 1 ,  2 ,  3  or  4 .  
     
     
         9 . A recombinant DNA molecule of  claim 8 , operatively linked to an expression control sequence.  
     
     
         10 . A host cell transformed with the recombinant DNA molecule of  claim 8 .  
     
     
         11 . A method for producing a modified CNTF molecule comprising: (a) growing a recombinant host cell containing the DNA molecule of  claim 8 , so that the DNA molecule is expressed by the host cell to produce the modified CNTF molecule and (b) isolating the expressed, modified CNTF molecule.  
     
     
         12 . The method according to  claim 11 , wherein said host cell is a eukaryotic cell.  
     
     
         13 . The method according to  claim 11 , wherein said host cell is a prokaryotic cell.  
     
     
         14 . A pharmaceutical composition comprising a therapeutically effective amount of a substantially pure modified ciliary neurotrophic factor according to  claim 1 ,  2 ,  3  or  4  in a pharmaceutically suitable carrier.  
     
     
         15 . A method of treating a disease or disorder of the nervous system comprising administering to a patient an effective amount of the modified ciliary neurotrophic factor of  claim 1 ,  2 ,  3  or  4 .  
     
     
         16 . The method according to  claim 15 , wherein said disease or disorder is a degenerative disease.  
     
     
         17 . The method according to  claim 15 , wherein said disease or disorder involves the spinal cord, motor neurons, cholinergic neurons or cells of the hippocampus.  
     
     
         18 . The method according to  claim 15 , in which the disease or disorder of the nervous system comprises damage to the nervous system caused by an event selected from the group consisting of trauma, surgery, infarction, infection, malignancy and exposure to a toxic agent.  
     
     
         19 . The method according to  claim 15 , wherein said disease or disorder involves muscle atrophy.  
     
     
         20 . A method of identifying a human protein with enhanced biological activity and/or binding affinity comprising: 
 (a) determining the SDS-PAGE electrophoretic mobility of a wild-type human protein;    (b) introducing an amino acid substitution in said wild-type human protein to produce a substituted protein;    (c) comparing the electrophoretic mobility of the substituted protein to the electrophoretic mobility of the wild-type protein;    (d) identifying a substituted protein with altered electrophoretic mobility as compared to the electrophoretic mobility of the wild-type protein; and    (e) determining the biological activity and/or binding affinity of the identified substituted protein and thereby identifying a human protein with enhanced biological activity and/or binding affinity.    
     
     
         21 . The method according to  claim 20 , wherein the amino acid substitution in the wild-type human protein corresponds to an amino acid found in a sequence of a homologous protein of a different animal species.