Hepatocyte growth factor fragments that function as potent met receptor agonists and antagonists

Abstract

The NK1 fragment of hepatocyte growth factor (HGF) binds to and activates the Met receptor, a transmembrane receptor tyrosine kinase that plays a critical role in embryonic development and organ formation. The instant application discloses NK1 variant polypeptides which act as agonists or antagonists of HGF. Further disclosed are covalently linked NK1 variant polypeptides. Many of the disclosed variant polypeptides possess improved stability characteristics.

1 .- 13 . (canceled) 
     
     
         14 . A dimer comprising a first human NK1 (hNK1) variant polypeptide and a second hNK1 variant polypeptide, wherein the first hNK1 variant polypeptide comprises a first linker and the second hNK1 polypeptide comprises a second linker, wherein the first linker comprises at least one cysteine residue and the second linker comprises a moiety reactive with a sulfhydryl group of the cysteine, wherein the dimer is formed by the reaction of cysteine with the moiety reactive with the sulfhydryl group. 
     
     
         15 .- 17 . (canceled) 
     
     
         18 . A method of tissue regeneration, said method comprising contacting cells with an effective amount of the dimer according to  claim 14 . 
     
     
         19 . A pharmaceutical formulation comprising the dimer of  claim 14  and a pharmaceutically acceptable carrier. 
     
     
         20 . The dimer according to  claim 14 , which is an agonist of Met. 
     
     
         21 . The dimer according to  claim 14 , which is a homodimer. 
     
     
         22 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides includes an amino acid substitution at amino acid position 62, 95, 132, 137, 170, 173, or 193. 
     
     
         23 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides includes an amino acid substitution selected from K137R, K170E, N193D, K62E, Q173R, Q95R, K132N/R, and combinations thereof. 
     
     
         24 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides comprises the amino acid substitution K62E. 
     
     
         25 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides comprises the amino acid substitution Q95R. 
     
     
         26 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides comprises the amino acid substitution K132N. 
     
     
         27 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides comprises the amino acid substitution K137R. 
     
     
         28 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides comprises the amino acid substitution K170E. 
     
     
         29 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides comprises the amino acid substitution Q173R. 
     
     
         30 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides comprises the amino acid substitution N193D. 
     
     
         31 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides comprises NK1 variant M2.2 D127N. 
     
     
         32 . The dimer according to  claim 14 , wherein both of said first and second NK1 variant polypeptides comprises NK1 variant M2.2 D127N. 
     
     
         33 . The dimer according to  claim 14 , wherein at least one of said first and second NK1 variant polypeptides comprises NK1 variant M2.2 D127K. 
     
     
         34 . The dimer according to  claim 14 , wherein both of said first and second NK1 variants of said dimer comprises NK1 variant M2.2 D127K. 
     
     
         35 . The dimer according to  claim 14 , which is cdD127N. 
     
     
         36 . The dimer according to  claim 14 , which is cdD127K.