Biotin-facilitated transport in gram negative bacteria

Abstract

Biotinylation of compounds such as peptides and peptidomimetics facilitates illicit transport of the compounds into Gram negative bacteria.

1 . A method for introducing a compound into a Gram negative bacterial cell, the method comprising contacting the cell with a biotinylated compound, wherein the compound comprises a peptide, and wherein the contact is effective to deliver the compound into the cytosol of the cell. 
     
     
         2 . A method for identifying a compound having antimicrobial activity comprising:
 contacting a Gram negative bacterial cell with a biotinylated compound, wherein the compound comprises a peptide, to cause uptake of the biotinylated compound into the cytosol of the cell; and   determining whether the compound has an antimicrobial effect on the cell.   
     
     
         3 . The method of  claim 1  or  2  further comprising linking a biotin moiety to the compound to yield the biotinylated compound. 
     
     
         4 . The method of  claim 1  or  2  wherein the peptide, prior to biotinylation, comprises a naturally occurring peptide. 
     
     
         5 . The method of  claim 1  or  2  wherein the peptide, prior to biotinylation, comprises a synthetic peptide 
     
     
         6 . The method of  claim 1  or  2  wherein the peptide is conjugated to first and second bioactive compounds, wherein the first bioactive compound comprises biotin. 
     
     
         7 . The method of  claim 1  or  2  wherein the Gram negative bacterial cell is a cell of the genus  Escherichia, Salmonella , or  Pseudomonas.    
     
     
         8 . The method of  claim 6  wherein the Gram negative bacterial cell is an  E. coli  cell, a  S. typhimurium  cell, or a  P. aeruginosa  cell. 
     
     
         9 . The method of  claim 1  or  2  wherein the Gram negative bacterial cell comprises a biotin transporter. 
     
     
         10 . The method of  claim 8  where the biotin transporter comprises a birB/bioP transporter. 
     
     
         11 . The method of  claim 1  or  2  wherein the compound comprises a therapeutic, diagnostic or imaging agent. 
     
     
         12 . The method of  claim 10  wherein the compound further comprises a targeting moiety that specifically targets a Gram negative bacterial cell. 
     
     
         13 . The method of  claim 11  wherein the targeting moiety comprises a receptor ligand or an antibody or fragment thereof. 
     
     
         14 . The method of  claim 10  wherein the compound comprises an antibiotic. 
     
     
         15 . The method of  claim 1  or  2  wherein the Gram negative bacterial cell is a pathogen. 
     
     
         16 . The method of  claim 1  or  2  wherein the peptide, when introduced into the cell, inhibits the growth of the cell. 
     
     
         17 . The method of  claim 1  or  2  wherein the peptide, when introduced into the cell, causes the death of the cell.