# Plugging & Pulling-in: tuning peptides for TolC to overcome antibiotic resistance

> **NIH NIH R01** · UNIVERSITY OF KANSAS LAWRENCE · 2024 · $65,000

## Abstract

SUMMARY
Summary of the parent R01GM148583-01A1: Antibiotic resistant infections already kill more people per year
than HIV/AIDS or malaria. Clinical antibiotic resistance is correlated with the overexpression of particular efflux
pumps. These efflux pumps shuttle out most classes of antibiotics so that the antibiotics can’t reach their
targets, reducing their effectiveness. The most accessible part of the efflux pump is its outer membrane barrel.
The outer membrane barrel accessibility makes it a good target for pharmaceutical development because it
can be accessed without getting through the often impermeable outer membrane. The efflux pump presents as
both a possible target for stopping antibiotic efflux and a possible avenue of drug delivery. Plugging efflux
pumps would make the antibiotics we already have work like new by stopping antibiotics from being removed
from the cell and allowing them to reach their targets. Hijacking the barrel for cellular import could be used to
deliver drugs that otherwise could not cross the bacterial outer membrane. Our long term goal is to develop
peptides to combat antibiotic resistant infection. The objective of the proposed research is to determine 1) what
protein-protein interactions are necessary to create high affinity plugs and 2) what protein-protein interactions
can facilitate peptide transit through the pump. We have recently solved the first structure of an exogenous
protein binding the outer membrane barrel of the E. coli antibiotic resistance. It is an unusual helix-in-barrel
structure. We have shown that the binding of this protein has some ability to act as a plug. It stops efflux and
make antibiotics more potent. We have also created databases of outer membrane barrels to better
understand the sequence structure relationships in these proteins. Here we propose to leverage these past
successes to 1) Identify common sequence and structural barrel-peptide interactions for antibiotic efflux pump-
like proteins 2) Screen for peptides that bind well to the E. coli antibiotic efflux pump and identify the features
that determine that binding, and 3) Identify what would facilitate the translocation of proteins across the efflux
pump that otherwise bind to the efflux pump. The global concept of this work, creating new plugs and
translocators for membrane β-barrels, has, to our knowledge, never been done before. The expected
outcomes of these experiments are a knowledge of how protein-protein interactions facilitate plugging and
pulling through of antibiotic efflux pumps, as well as the creation of peptides that plug or pull through TolC. This
work is poised to make a significant contribution because it will demonstrate the important protein-protein
interactions necessary to create membrane protein plugs and translocators and can thereby enable a revival of
existing antibiotics against resistant superbugs.

## Key facts

- **NIH application ID:** 11100928
- **Project number:** 3R01GM148583-02S1
- **Recipient organization:** UNIVERSITY OF KANSAS LAWRENCE
- **Principal Investigator:** Joanna SG Slusky
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $65,000
- **Award type:** 3
- **Project period:** 2023-08-05 → 2027-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11100928

## Citation

> US National Institutes of Health, RePORTER application 11100928, Plugging & Pulling-in: tuning peptides for TolC to overcome antibiotic resistance (3R01GM148583-02S1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/11100928. Licensed CC0.

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