Methods, peptides and biosensors useful for detecting a broad spectrum of bacteria

Abstract

Described herein are methods of detecting a wound infection and for detecting the presence or absence of bacteria, for example, wound bacteria in a sample, by contacting a sample with a peptide substrate derived from the modification of the reactive site loop (RSL) domain of the α1-proteinase inhibitor. In the current invention, we have demonstrated that these peptide substrates without the alpha 1 protein can be efficiently used as peptide substrates. The modification or the absence of modification of this peptide substrate by the enzyme produced and/or secreted by the bacteria, can serve as an indicator for the presence or absence of the bacteria in the sample. The present invention also features a biosensor for detecting the presence or absence of bacteria in a sample.

1 . An isolated peptide comprising a detectable label and an amino acid sequence selected from the group consisting of EAAGAMFLEAIPK, EGAMFLEAIPMSIPK, KGTEAAGAMFLEAIPMSIPPEVK, GAMFLEAIPMSIPPE, and CGAMFLEAIPMSIPAAAHHHHH. 
     
     
         2 . The peptide of  claim 1  labeled with a fluorescent probe and a quencher dye molecule. 
     
     
         3 . The peptide of  claim 1  wherein the detectable label is selected from the group consisting of spin labels, antigen tags, epitope tags, haptens, enzyme labels, prosthetic groups, fluorescent materials, pH-sensitive materials, chemiluminescent materials, colorimetric components, bioluminescent materials, and radioactive materials.