R01AI165782

Transport Mechanisms and Inhibition of Efflux Pumps in Pathogenic Organisms - Project Summary

The long-term goal of our research is to develop first-in-class, protein-based inhibitors against human bacterial pathogens by directly blocking efflux pumps. Drug-resistant bacteria pose an urgent global health challenge by reducing the effectiveness of antibiotics used to treat infections in humans and animals.

The broadest resistance mechanism against antibiotics are efflux pumps, which transport drugs out of the cytoplasm and reduce toxicity to the organism. While it is known that efflux pumps display broad specificity to structurally distinct compounds, the mechanisms of polyspecific drug binding and ion-coupled transport remain unanswered questions in the field. Given the promiscuity of efflux pump binding to structurally distinct drugs, it is also unclear whether potent and selective efflux pump inhibitors can be designed to target specific classes of efflux pumps.

The specific goals of this project are to discover novel mechanisms of active transport in drug-resistant Staphylococcus aureus and to harness this knowledge to design selective inhibitors toward efflux pumps. Our proposal is strongly motivated by our recent discovery of antibody fragments (Fabs) that bind the Staphylococcus aureus efflux pump NORA and successful determination of high-resolution cryo-EM structures using the Fabs as fiduciaries. The structures revealed that the Fabs insert a loop into the substrate binding pocket from the extracellular side, which suggests a design path toward protein- and peptide-based inhibitors. This interaction is facilitated by an electrostatic interaction between a positively charged arginine on the Fab and two essential anionic residues within NORA.

Building on these preliminary data, we propose to carry out four specific aims. Aim 1 will develop a hybrid approach of cryo-electron microscopy and NMR spectroscopy to comprehensively study the transport cycle of NORA. Aim 2 will seek to determine the molecular basis for polyspecific drug binding. Aim 3 will design and characterize protein-based inhibitors that target the accessible, outward-open conformation of NORA. Aim 4 will develop peptides that miniaturize the antibody loops observed in the binding pocket of NORA.

We have assembled an interdisciplinary team with expertise in structural biology, protein engineering, microbiology, chemical synthesis, and computational chemistry to rapidly answer fundamental questions about multidrug transport and inhibition of efflux pumps. All of the approaches applied to NORA will be translational to other transporter systems.

New York University

TO ASSIST PUBLIC AND PRIVATE NONPROFIT INSTITUTIONS AND INDIVIDUALS TO ESTABLISH, EXPAND AND IMPROVE BIOMEDICAL RESEARCH AND RESEARCH TRAINING IN INFECTIOUS DISEASES AND RELATED AREAS, TO CONDUCT DEVELOPMENTAL RESEARCH, TO PRODUCE AND TEST RESEARCH MATERIALS. TO ASSIST PUBLIC, PRIVATE AND COMMERCIAL INSTITUTIONS TO CONDUCT DEVELOPMENTAL RESEARCH, TO PRODUCE AND TEST RESEARCH MATERIALS, TO PROVIDE RESEARCH SERVICES AS REQUIRED BY THE AGENCY FOR PROGRAMS IN INFECTIOUS DISEASES, AND CONTROLLING DISEASE CAUSED BY INFECTIOUS OR PARASITIC AGENTS, ALLERGIC AND IMMUNOLOGIC DISEASES AND RELATED AREAS. PROJECTS RANGE FROM STUDIES OF MICROBIAL PHYSIOLOGY AND ANTIGENIC STRUCTURE TO COLLABORATIVE TRIALS OF EXPERIMENTAL DRUGS AND VACCINES, MECHANISMS OF RESISTANCE TO ANTIBIOTICS AS WELL AS RESEARCH DEALING WITH EPIDEMIOLOGICAL OBSERVATIONS IN HOSPITALIZED PATIENTS OR COMMUNITY POPULATIONS AND PROGRESS IN ALLERGIC AND IMMUNOLOGIC DISEASES. BECAUSE OF THIS DUAL FOCUS, THE PROGRAM ENCOMPASSES BOTH BASIC RESEARCH AND CLINICAL RESEARCH. SMALL BUSINESS INNOVATION RESEARCH (SBIR) PROGRAM EXPANDS AND IMPROVES PRIVATE SECTOR PARTICIPATION IN BIOMEDICAL RESEARCH. THE SBIR PROGRAM INTENDS TO INCREASE AND FACILITATE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, TO INCREASE SMALL BUSINESS PARTICIPATION IN FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. THE SMALL BUSINESS TECHNOLOGY TRANSFER (STTR) PROGRAM STIMULATES AND FOSTERS SCIENTIFIC AND TECHNOLOGICAL INNOVATION THROUGH COOPERATIVE RESEARCH AND DEVELOPMENT CARRIED OUT BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO FOSTER TECHNOLOGY TRANSFER BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO INCREASE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. RESEARCH CAREER DEVELOPMENT AWARDS SUPPORT THE DEVELOPMENT OF SCIENTISTS DURING THE FORMATIVE STAGES OF THEIR CAREERS. INDIVIDUAL NATIONAL RESEARCH SERVICE AWARDS (NRSAS) ARE MADE DIRECTLY TO APPROVE APPLICANTS FOR RESEARCH TRAINING IN SPECIFIED BIOMEDICAL SHORTAGE AREAS. IN ADDITION, INSTITUTIONAL NATIONAL RESEARCH SERVICE AWARDS ARE MADE TO ENABLE INSTITUTIONS TO SELECT AND MAKE AWARDS TO INDIVIDUALS TO RECEIVE TRAINING UNDER THE AEGIS OF THEIR INSTITUTIONAL PROGRAM.

93.855 - Allergy and Infectious Diseases Research

National Institute of Allergy and Infectious Diseases (NIAID) [HHS - NIH]

New York, New York 100122338 United States

Single Zip Code

NIH Research Project Grant (Parent R01 Clinical Trial Not Allowed) (PA-20-185)

Amendment Since initial award the total obligations have increased 322% from $743,532 to $3,135,598.