IdeS, an IgG-degrading enzyme of Streptococcus pyogenes

Abstract

A polypeptide isolated from S. pyogenes is described, having IgG cysteine protease activity. The protease is designated IdeS, Immunoglobulin G-degrading enzyme of S. pyogenes. A polypeptide comprises SEQ ID NO: 1 and variants and fragments thereof having IgG cysteine protease activity or the ability to generate an immune response against S. pyogenes in an individual. Polynucleotides encoding these polypeptides and the polypeptides may be used in generating an immune response in an individual. IdeS protease inhibitors may be used in the treatment of S. pyogenes infection.

1 . A polypeptide comprising: 
 (a) the amino acid sequence of SEQ ID NO: 1;    (b) a variant thereof having at least 50% identity to the amino acid sequence of SEQ ID NO: 1 and having IgG cysteine protease activity;    (c) a fragment of either thereof having IgG cysteine protease activity; or    (d) a fragment of (a) or (b) which is capable of generating an immune response to  S. pyogenes  in an individual.    
     
     
         2 . A polypeptide according to  claim 1 , wherein said variant has at least 80% identity to SEQ ID NO: 1.  
     
     
         3 . A polypeptide according to  claim 2 , wherein said variant has at least 95% identity to SEQ ID NO: 1.  
     
     
         4 . A polypeptide according to  claim 3 , wherein said variant has at least 97% identity to SEQ ID NO: 1.  
     
     
         5 . A polypeptide according to  claim 4 , wherein said variant has at least 99% identity to SEQ ID NO: 1.  
     
     
         6 . A polypeptide according to  claim 1 , wherein said fragment is a fragment of at least 50 amino acids in length.  
     
     
         7 . A polypeptide according to  claim 6 , wherein said fragment is a fragment of at least 100 amino acids in length.  
     
     
         8 . A polypeptide according to  claim 7 , wherein said fragment is a fragment of at least 200 amino acids in length.  
     
     
         9 . A pharmaceutical composition comprising a pharmaceutically acceptable carrier and/or diluent and a polypeptide according to  claim 1 .  
     
     
         10 . A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a polypeptide according to  claim 1 , wherein said composition is a vaccine composition.