Genetically engineered glutaminase and its use in antiviral and anticancer therapy

Abstract

DNA encoding a therapeutically suitable glutaminase has been molecularly cloned. This allows one to obtain a polypeptide which is a therapeutically suitable glutaminase free of contaminating endotoxin. It has been found that this polypeptide is a potent anti-viral agent and when coupled to an anti-tumor monoclonal antibody is a potent anti-cancer agent. The gluatminase of the present invention is particularly useful for treating lung, breast and colon cancer cells and in the treatment of HIV-infected cells.

1 . A cell-free preparation of a therapeutically suitable glutaminase which is free of  Pseudomonas  endotoxin.  
     
     
         2 . The preparation of  claim 1 , wherein said glutaminase is a  Pseudomonas  glutaminase.  
     
     
         3 . The preparation of  claim 1 , wherein said glutaminase is a  Pseudomonas  7a glutaminase.  
     
     
         4 . The preparation of  claim 1 , which is free of non-glutaminase  Pseudomonas  proteins.  
     
     
         5 . The preparation of  claim 1 , which is made by the process of: 
 culturing a recombinant microorganism which comprises a nucleotide sequence that codes for a therapeutically suitable glutaminase; and    collecting said therapeutically suitable glutaminase produced by said microorganism.    
     
     
         6 . The preparation of  claim 1 , wherein said glutaminase has the sequence shown in SEQ ID NO:2.  
     
     
         7 . The preparation of  claim 3 , which has an initial methionine preceding the initial lysine of mature glutaminase.  
     
     
         8 . The preparation of  claim 6 , wherein said glutaminase is encoded by the nucleotide sequence of SEQ ID NO: 1.  
     
     
         9 . The preparation of  claim 1 , wherein said glutaminase has a K m  of 10 −6  to 10 −4  M for its reactants and remains active in human sera.  
     
     
         10 . The preparation of  claim 1 , wherein said microorganism is a bacterium.  
     
     
         11 . The preparation of  claim 10 , wherein said microorganism is  E. coli.