Engineering membrane-selective antibiotic peptides to combat multidrug resistance

Antibiotic resistance is a global health emergency that mandates new drug development strategies. Natural antimicrobial peptides (AMPs) have been long-recognized as a potential source of bacteriolytic drugs, but the shortcomings of non-specific membrane toxicity, proteolytic instability, and in vivo toxicity have stymied their clinical translation. Here, we subjected expansive stapled-peptide libraries of the magainin II (Mag2) AMP to structure-function analyses and uncovered the biophysical and mechanistic determinants that allow for the rational design of stapled AMPs (StAMPs) that are bacterial-membrane selective, proteolytically-stable, well tolerated in mice upon intravenous administration, and most importantly, overcome even the most antibiotic-resistant bacteria, including colistin-resistant A. baumannii and mobilized colistin resistance plasmid-bearing E. coli. Specifically, we discovered that the topographic continuity and strength of hydrophobic networks, in the context of alpha-helical amphipathic cationic peptides, dictates both the selectivity and mechanism of membrane lysis. We further harnessed our results to develop an algorithm for the design of a new generation of non-toxic, bacterial-selective StAMPs for clinical development.

Name thesis:degree_name

Doctoral

Department dc:contributor.department

Harvard University--MIT Division of Health Sciences and Technology

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2018

Author dc:creator

• Mourtada, Rida.

Advisor dc:contributor.advisor

• Loren D. Walensky.

• Harvard--MIT Program in Health Sciences and Technology.

Statement dc:rights

• MIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/132987

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/132987