TY - JOUR
T1 - Hybrid peptide ATCUN-sh-Buforin
T2 - Influence of the ATCUN charge and stereochemistry on antimicrobial activity
AU - Libardo, M. Daben J.
AU - Paul, Thomas J.
AU - Prabhakar, Rajeev
AU - Angeles-Boza, Alfredo M.
N1 - Funding Information:
This material is based upon work supported by the National Science Foundation (grant no. 1152846 ) to R.P., and the University of Connecticut start-up funds to A.M.A.-B. We would like to thank Prof. Kim Lewis and Alyssa Theodore (Northeastern University) for generously providing the E. coli strains used in these studies. We thank Dr. Carol Norris (U. Connecticut Biotechnology/Bioservices Center) for her help with the flow cytometry experiments. The authors would also like to acknowledge Dr. Kenneth Campellone and Dr. Jorge Cervantes for the generous gift of HeLa and HEK293 cells, respectively.
Publisher Copyright:
© 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.
PY - 2015/6/1
Y1 - 2015/6/1
N2 - The emergence of antibiotic resistant strains of bacteria has resulted in the need to develop more potent antimicrobials that target microorganisms in a novel manner. Antimicrobial Peptides (AMPs) show great potential for drug development because of their broad activity and unique mechanism of action. Several AMPs contain an Amino Terminal Copper and Nickel (ATCUN) binding motif; however, its function has not yet been determined. We have previously demonstrated that the activity of a truncated version of Buforin II (sh-Buforin, RAGLQFPVGRVHRLLRK-NH2) increases by the addition of an ATCUN motif. We now focus our current studies on understanding the effect of: 1) a positively charged ATCUN sequence, and 2) l-to-d amino acid substitution on the hybrid peptides. We identified that the addition of a positively charged ATCUN motif increases the affinity of the ATCUN-AMP for DNA but does not always result in an enhanced antimicrobial activity over a neutral ATCUN motif. The all-d peptides exhibited up to a 32-fold increase in antimicrobial activity compared to the all-l peptides. The larger activity of the all-d peptides is the result of a larger DNA cleavage activity and higher stability towards proteolysis. Cytotoxicity assays determined that, at their MIC, these peptides caused less than 8% hemolysis and, at 128 μM, no toxicity to HeLa and HEK293 cell lines. These results indicate that the ATCUN-AMP hybrids are an attractive alternative for treating infectious diseases and provide key insights into the role of the ATCUN motif in naturally-occurring AMPs.
AB - The emergence of antibiotic resistant strains of bacteria has resulted in the need to develop more potent antimicrobials that target microorganisms in a novel manner. Antimicrobial Peptides (AMPs) show great potential for drug development because of their broad activity and unique mechanism of action. Several AMPs contain an Amino Terminal Copper and Nickel (ATCUN) binding motif; however, its function has not yet been determined. We have previously demonstrated that the activity of a truncated version of Buforin II (sh-Buforin, RAGLQFPVGRVHRLLRK-NH2) increases by the addition of an ATCUN motif. We now focus our current studies on understanding the effect of: 1) a positively charged ATCUN sequence, and 2) l-to-d amino acid substitution on the hybrid peptides. We identified that the addition of a positively charged ATCUN motif increases the affinity of the ATCUN-AMP for DNA but does not always result in an enhanced antimicrobial activity over a neutral ATCUN motif. The all-d peptides exhibited up to a 32-fold increase in antimicrobial activity compared to the all-l peptides. The larger activity of the all-d peptides is the result of a larger DNA cleavage activity and higher stability towards proteolysis. Cytotoxicity assays determined that, at their MIC, these peptides caused less than 8% hemolysis and, at 128 μM, no toxicity to HeLa and HEK293 cell lines. These results indicate that the ATCUN-AMP hybrids are an attractive alternative for treating infectious diseases and provide key insights into the role of the ATCUN motif in naturally-occurring AMPs.
KW - ATCUN
KW - Antimicrobial peptide
KW - Bioinorganic chemistry
KW - Cytotoxicity
KW - Reactive oxygen species
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U2 - 10.1016/j.biochi.2015.04.008
DO - 10.1016/j.biochi.2015.04.008
M3 - Article
C2 - 25891844
AN - SCOPUS:84928529694
VL - 113
SP - 143
EP - 155
JO - Biochimie
JF - Biochimie
SN - 0300-9084
ER -