Novel method of detecting and isolating prion protein and variants thereof, and novel methods of diagnosing and treating prion diseases

Abstract

The present invention provides for a novel method of detecting the prion protein and variants thereof which utilizes specific amino acid binding sequences. Specifically, the present invention provides a method of detecting prion proteins, as well as isolating prion proteins, using an agent that binds to the amino acid sequence Gln-Pro-His of prion proteins. Further provided by the present invention is a method of diagnosing prion diseases in a subject using an agent that binds to the amino acid sequence Gln-Pro-His of prion proteins. Also provided are methods of treating and preventing prion diseases in a subject by administering an agent that binds to the amino acid sequence Gln-Pro-His of prion proteins. Finally, a method of inhibiting the dissemination of prion diseases through ingestion or exposure to liquid or solid substances by treating of the liquid or solid substance with biotin is provided herein.

What is claimed is:  
     
         1 . A method of detecting the presence of prion protein in a sample comprising contacting said sample with an agent which binds to the amino acid sequence Gln-Pro-His of prion protein and detecting said agent bound to said prion protein.  
     
     
         2 . The method of  claim 1  wherein the prion protein is PrP c  protein, PrP sc  protein, or a variant thereof.  
     
     
         3 . The method of  claim 1  wherein the agent is a protein, peptide, polypeptide, nucleic acid, non-peptide organic molecule or organic reagent.  
     
     
         4 . The method of  claim 3  wherein the protein is streptavidin.  
     
     
         5 . The method of  claim 4  wherein the streptavidin is bound to a detectable marker.  
     
     
         6 . The method of  claim 5  wherein the detectable marker is selected from the group consisting of a fluorescence marker, an enzyme, or a radiolabeled marker.  
     
     
         7 . The method of  claim 6  wherein the enzyme is phosphatase.  
     
     
         8 . The method of  claim 1  wherein said sample is blood, plasma, serum, cerebrospinal fluid, brain tissue, cornea tissue, urine, fecal matter, soil, bone meal, beef, beef by-products, sheep, sheep by-products, deer, deer by-products, elk, elk by-products, water or milk.  
     
     
         9 . The method of  claim 1  wherein the prion protein is detected by electrophoretic separation on a denaturing gel.  
     
     
         10 . The method of  claim 9 , wherein the denaturing gel is a urea polyacrylamide gel.  
     
     
         11 . A method of isolating prion protein in a sample comprising contacting said sample with an agent which binds to the amino acid sequence Gln-Pro-His of prion protein under conditions permitting said agent to bind to prion protein and isolating prion protein bound to said agent.  
     
     
         12 . The method of  claim 11  wherein the prion protein is PrP c  protein, PrP sc  protein, or a variant thereof.  
     
     
         13 . The method of  claim 11  wherein the agent is a protein, peptide, polypeptide, nucleic acid, non-peptide organic molecule or an organic reagent.  
     
     
         14 . The method of  claim 13  wherein the protein is streptavidin.  
     
     
         15 . The method of  claim 14  wherein the streptavidin is bound to a detectable marker.  
     
     
         16 . The method of  claim 15  wherein the detectable marker is selected from the group consisting of a fluorescence marker, an enzyme, or a radiolabeled marker.  
     
     
         17 . The method of  claim 16  wherein the enzyme is phosphatase.  
     
     
         18 . The method of  claim 11  wherein the agent which binds to the amino acid sequence Gln-Pro-His is bound to a solid support.  
     
     
         19 . A prion protein detectable kit comprising an agent which binds to the amino acid sequence Gln-Pro-His of prion protein.  
     
     
         20 . The kit of  claim 19  wherein the prion protein is PrP c  protein, PrP sc  protein, or a variant thereof.  
     
     
         21 . The kit of  claim 19  wherein the agent is a protein, peptide, polypeptide, nucleic acid, non-peptide organic molecule or organic reagent.  
     
     
         22 . The kit of  claim 19  wherein the agent is streptavidin.  
     
     
         22 . The kit of  claim 22  wherein the streptavidin is bound to a detectable marker.  
     
     
         23 . The kit of  claim 22  wherein the detectable marker is selected from the group consisting of a fluorescence marker, an enzyme, or a radiolabeled marker.  
     
     
         24 . The kit of  claim 23  wherein the enzyme is phosphatase.  
     
     
         25 . A method for diagnosing a disease condition caused by an infectious prion protein in a subject comprising the steps of: 
 (a) contacting a biological sample from the subject with an agent which binds to the amino acid sequence Gln-Pro-His of prion protein; and    (b) detecting formation of a complex between said prion protein and said agent, if present in said biological sample.    
     
     
         26 . The method of  claim 25  wherein the prion protein is PrP c  protein, PrP sc  protein, or a variant thereof.  
     
     
         27 . The method of  claim 25  wherein the agent is a protein, peptide, polypeptide, nucleic acid, non-peptide organic molecule or an organic reagent.  
     
     
         28 . The method of  claim 27  wherein the protein is streptavidin.  
     
     
         29 . The method of  claim 25  wherein said biological sample is blood, plasma, serum, cerebrospinal fluid, brain tissue, cornea tissue, urine or fecal matter.  
     
     
         30 . A method for treating or preventing a disease condition caused by an infectious prion protein in a subject comprising administering to said subject an amount of an agent which binds to the amino acid sequence Gln-Pro-His of prion protein effective to treat or prevent the prion disease.  
     
     
         31 . The method of  claim 30  wherein the agent is a protein, peptide, polypeptide, nucleic acid, non-peptide organic molecule or organic reagent.  
     
     
         32 . The method of  claim 30 , wherein the prion disease is Creutzfeld-Jakob disease, variant Creutzfeld-Jakob disease, Gerstmann-Sträussler-Scheinker disease, fatal familial insomnia, scrapie, bovine spongiform encephalopathy (mad cow disease), transmissible mink encephalopathy, feline spongiform encephalopathy, exotic ungulate encephalopathy, or chronic wasting disease.  
     
     
         33 . A method for inhibiting the dissemination of prion protein disease comprising inactivating streptavidin that may be contained in a physical substance by treating the physical substance with an amount of biotin, or a derivative thereof, effective to bind to the streptavidin, if present in the physical substance.  
     
     
         34 . The method of  claim 33 , wherein the physical substance is a liquid or a solid substance.  
     
     
         35 . The method of  claim 33 , wherein the liquid substance is water, milk or juice.  
     
     
         36 . The method of  claim 34 , wherein the solid substance is meat, meat by-products, animal feed, or soil.  
     
     
         37 . A method for treating a prion disease in a subject comprising administering to the subject an amount of biotin, or a derivative thereof, effective to treat the prion disease in the subject.  
     
     
         38 . The method of  claim 37 , wherein the prion disease is Creutzfeld-Jakob disease, variant Creutzfeld-Jakob disease, Gerstmann-Sträussler-Scheinker disease, fatal familial insomnia, scrapie, bovine spongiform encephalopathy (mad cow disease), transmissible mink encephalopathy, feline spongiform encephalopathy, exotic ungulate encephalopathy, or chronic wasting disease.  
     
     
         39 . The method of  claim 37  wherein the biotin is administered intravenously or by ingestion.  
     
     
         40 . The method of  claim 37 , wherein the subject is a human or an animal.  
     
     
         41 . A method for screening for an agent which binds to the amino acid sequence Gln-Pro-His of the human prion protein comprising detecting the presence of the agent bound to the prion protein.  
     
     
         42 . A method for screening for an agent that binds to two or more prion proteins comprising the steps of (1) combining infectious and noninfectious prion protein to form a protein mixture; (2) adding to the protein mixture a sample containing a potential agent that binds to two or more prion proteins; and (3) comparing the resulting levels of infectious and noninfectious prion protein to the initial levels combined.