# Targeting Burkholderial β-lactamases: Structure, function, and regulation

> **NIH VA I01** · LOUIS STOKES CLEVELAND VA MEDICAL CENTER · 2021 · —

## Abstract

The prevalence of the Burkholderia cepacia complex (Bcc), a group of multidrug-resistant (MDR) pathogens, is
predicted to significantly increase in patients with pulmonary disorders (e.g., chronic obstructive pulmonary
disease (COPD), cystic fibrosis (CF), and asthma) by 2024. Moreover, MDR Bcc isolates that are resistant to
all currently recommended therapies are emerging. Unfortunately, the development of novel drugs against MDR
Bcc is lacking as is our understanding of these unique pathogens. In a retrospective study, a 35% mortality rate
in Veterans that acquired a Bcc infection was observed. Additionally, Veterans are shown to be
disproportionately affected by COPD, which puts them at an increased risk of acquiring infections by Bcc.
Indeed, the number of Bcc outbreaks around the world has doubled over the last decade. Identifying novel
strategies to overcome antibiotic resistance in these highly complex organisms that possess multiple
chromosomes is a significant unmet medical need and a substantial scientific challenge.
 β-Lactams are one of the most prescribed and safest class of antibiotics and are often used to treat Bcc
infections. However, the production of β-lactamases is the most prevalent β-lactam-resistance mechanism in
members of the Bcc, which possess two chromosomally-encoded inducible β-lactamases, blapenA and blaampC.
As a result, the main objective of this application is to identify novel ways of overcoming β-lactam resistance in
Bcc. Building upon studies performed previously, mechanism-based approaches will be used to selectively
inhibit the following proteins in Bcc: 1. PenA, a versatile carbapenemase; 2. AmpC, a unique cephalosporinase;
3. Penicillin binding proteins (PBPs), the biological target of β-lactams and whose inhibition is linked to bla (β-
lactamase gene) expression; and 4. PenRA, the transcription regulator of bla genes.
 To address these objectives, a mechanism-based approach will be used to restore susceptibility to MDR
Bcc by testing selected β-lactams alone and in combination with β-lactamase inhibitors, performing biochemical
and structural analysis of PenA and AmpC with the β-lactams and β-lactamase inhibitors, analyzing the genomes
of MDR Bcc, and determining the in vivo efficacy of selected combinations. Moreover, the link between PBP
inhibition and bla expression will be deciphered by identifying which β-lactams effect bla expression, measuring
the binding of β-lactams to PBPs, visualizing cells exposed to β-lactams via microscopy to reveal the impact of
β-lactams on cell morphology, and constructing pbp gene knockouts and assessing their phenotypes. In
addition, PenRA will be targeted for inhibition in B. multivorans by using crystallography to define the binding
pocket of the PenRA effector binding domain (EBD) and conducting a targeted small molecule inhibitor library
screen using an in-house high-throughput fluorescence assay.
 The anticipated outcomes include identifying novel combinations to in...

## Key facts

- **NIH application ID:** 10045919
- **Project number:** 5I01BX002872-06
- **Recipient organization:** LOUIS STOKES CLEVELAND VA MEDICAL CENTER
- **Principal Investigator:** KRISZTINA Margaret PAPP-WALLACE
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2021
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2015-10-01 → 2023-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10045919

## Citation

> US National Institutes of Health, RePORTER application 10045919, Targeting Burkholderial β-lactamases: Structure, function, and regulation (5I01BX002872-06). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10045919. Licensed CC0.

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