A technology for developing synbodies with antibacterial activity

PLoS One. 2013;8(1):e54162. doi: 10.1371/journal.pone.0054162. Epub 2013 Jan 23.

Abstract

The rise in antibiotic resistance has led to an increased research focus on discovery of new antibacterial candidates. While broad-spectrum antibiotics are widely pursued, there is evidence that resistance arises in part from the wide spread use of these antibiotics. Our group has developed a system to produce protein affinity agents, called synbodies, which have high affinity and specificity for their target. In this report, we describe the adaptation of this system to produce new antibacterial candidates towards a target bacterium. The system functions by screening target bacteria against an array of 10,000 random sequence peptides and, using a combination of membrane labeling and intracellular dyes, we identified peptides with target specific binding or killing functions. Binding and lytic peptides were identified in this manner and in vitro tests confirmed the activity of the lead peptides. A peptide with antibacterial activity was linked to a peptide specifically binding Staphylococcus aureus to create a synbody with increased antibacterial activity. Subsequent tests showed that this peptide could block S. aureus induced killing of HEK293 cells in a co-culture experiment. These results demonstrate the feasibility of using the synbody system to discover new antibacterial candidate agents.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Anti-Bacterial Agents / chemical synthesis*
  • Anti-Bacterial Agents / pharmacology
  • Bacillus subtilis / drug effects*
  • Bacillus subtilis / growth & development
  • Coculture Techniques
  • Escherichia coli / drug effects*
  • Escherichia coli / growth & development
  • Fluorescent Dyes
  • HEK293 Cells
  • High-Throughput Screening Assays
  • Humans
  • Microbial Sensitivity Tests
  • Peptide Library*
  • Protein Array Analysis
  • Protein Binding
  • Pseudomonas aeruginosa / drug effects*
  • Pseudomonas aeruginosa / growth & development
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / growth & development

Substances

  • Anti-Bacterial Agents
  • Fluorescent Dyes
  • Peptide Library

Grants and funding

This work was supported by a grant from DARPA (http://www.darpa.mil/) under the 7 Day Biodefense Program to SAJ (grant number W911NF-10-1-0299). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.