# D-peptide Inhibitors of Uropathogenic E. coli Adhesion Proteins to Treat Urinary Tract Infections

> **NIH NIH F31** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 2022 · $40,212

## Abstract

PROJECT SUMMARY
 Adhesion proteins on the pilus-covered surface of Uropathogenic E. coli (UPEC) are required for attachment
to host cells to facilitate colonization and disease progression in urinary tract infections (UTIs). The primary
adhesion proteins associated with UPEC virulence are FimH, which binds D-mannose on uroepithelial cells, and
FmlH, which binds N-acetylgalactosamine on kidney and inflamed bladder cells. This proposal aims to develop
UTI treatments that prevent the attachment and subsequent internalization of UPEC in uroepithelial cells,
eliminating bacteria from the urinary tract. Treatments that block the highly conserved binding pockets of
FimH/FmlH prevent UPEC attachment to host cells and clear bacteria from the urinary tract6,9,11. However,
designing inhibitors that reach the urinary tract to reduce the risk for recurrent infections (e.g., through a long
half-life and without disrupting commensal bacteria) remains challenging. Our goal is to use mirror-image phage
display to identify D-peptide inhibitors of UPEC adhesion to eliminate bacteria from the urinary tract. We
hypothesize that D-peptide inhibitors that prevent attachment to host cells could serve as novel
antibiotic-sparing UTI treatments. D-peptides are ideal for this application because they are cleared via kidney
filtration (accumulate in urine), have a long half-life, and can be formulated as a long-acting injection.
 To screen for D-peptide inhibitors, we will first chemically synthesize the mirror-image D-target proteins
(FimH/FmlH) using solid-phase peptide synthesis (SPPS) with D-amino acids and native chemical ligation (NCL).
These D-proteins will be validated by comparison to recombinant L-proteins for secondary structure and binding
activity. Using mirror-image phage display, we will screen diverse phage libraries for L-peptide binders to the
synthesized D-target proteins. Next-generation sequencing (NGS) will be used to identify high-affinity hits that
will then be synthesized in D- to inhibit the natural L-target.
 We will determine the affinity of our inhibitors via direct binding and competition studies. The crystal structures
of our D-peptides in complex with FimH or FmlH will be obtained using X-ray crystallography and will inform
inhibitor affinity optimization. In vitro assays will be performed using a panel of 40 UPEC strains to validate D-
peptide inhibition of host cell attachment, hemagglutination, and biofilm formation. We will determine the
pharmacokinetic (PK) profile of the most promising D-peptides in mice. Finally, we will evaluate the efficacy of
treatments in mouse acute and chronic UTI models. This project will contribute valuable information about UPEC
pili binding interactions, advance our chemical protein synthesis knowledge, and generate D-peptide inhibitor
leads for precision UTI treatment.

## Key facts

- **NIH application ID:** 10466391
- **Project number:** 1F31AI167609-01A1
- **Recipient organization:** UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH
- **Principal Investigator:** Marcy Robins
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $40,212
- **Award type:** 1
- **Project period:** 2022-09-01 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10466391

## Citation

> US National Institutes of Health, RePORTER application 10466391, D-peptide Inhibitors of Uropathogenic E. coli Adhesion Proteins to Treat Urinary Tract Infections (1F31AI167609-01A1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10466391. Licensed CC0.

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