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Principal Investigator: Kate Suzanne Carroll
Organization: UNIVERSITY OF FLORIDA
Fiscal Year: 2024
Award: $1
Funding agency: National Institute of General Medical Sciences
PROJECT SUMMARY
Antibiotics are central to modern medicine and rising antibiotic resistance is one of the biggest threats to global health.
Identifying new and different drug targets for the development of new antibiotics is crucial to overcome resistance.
Adjuvant strategies that either enhance the activity of existing antibiotics or improve clearance by the host immune
system provide another mechanism to combat antibiotic resistance. Targeting a combination of essential and non-
essential enzymes that play key roles in bacterial metabolism is a promising strategy to develop new antimicrobials
and adjuvants, respectively. The enzymatic synthesis of L-cysteine is one such strategy. Cysteine plays a key role in
proteins and is vital to the synthesis of biomolecules important for defense against the host immune system. In contrast
to mammals, the biosynthesis of cysteine occurs de novo in microbes using sulfide (S2–) as the sulfur source derived
from the reductive sulfate assimilation pathway. Inhibition of sulfate assimilation has been proven to interfere with a
pathogen’s ability to fight oxidative stress, infect the host and establish long-term infection. Inhibition of sulfate assim-
ilation has also been associated with a dysregulated oxidative stress response, enhancing the antimicrobial activity of
existing antibiotics. In previous funding cycles, we have defined the mechanism and structure of mycobacterial 5’-
adenylylsulfate (APS) reductase an iron-sulfur protein that catalyzes the two-electron reduction of APS to sulfite (SO32–
) using thioredoxin (TrxA) as the preferred electron donor. We subsequently used these insights to discover first-in-
class inhibitors of mycobacterial APS reductase (APR), with potent in vivo bactericidal activity against MDR and XDR
clinical isolates of Mycobacterium tuberculosis (Mtb) and synergistic activity with known anti-TB drugs (isoniazid, ri-
fampicin, clofazimine) in killing H37Rv Mtb. In this renewal, we now seek to expand our early focus on cysteine bio-
synthesis and redox metabolism in mycobacteria to pathogens implicated in fatal secondary bacterial infections in
influenza infection, specifically in patients with COVID-19: Pseudomonas aeruginosa and Streptococcus pneumoniae.
Given the importance of microbial sulfur metabolism in oxidative stress resistance and virulence, in this renewal ap-
plication we propose the following Specific Aims: (1) Define the mechanistic and structural basis for inhibition of the
Fe-S protein APR from P. aeruginosa; (2) Investigate the effect of P. aeruginosa APR inhibitors on sulfur metabolism
and redox metabolism in cells; (3) Determine whether a virus family that infect S. pneumoniae in human environments
and encode genes for reductive sulfate assimilation increase the fitness of the bacterial host, which lacks this pathway.
Terms: <Active Sites><Acute><Address><Adjuvant><Adrenodoxin Reductase><Aerobic Bacteria><Allelism Test><Amino Acids><Anabolism><Anti-Bacterial Agents><Antibiotic Agents><Antibiotic Drugs><Antibiotic Resistance><Antibiotics><Antitubercular Drugs><Attention><B catarrhalis><B. catarrhalis><Bacteria><Bacterial Infections><Bacteriophages><Basic Research><Basic Science><Benemycin><Branhamella catarrhalis><Buccal Cavity><Buccal Cavity Head and Neck><COVID infected patient><COVID patient><COVID positive patient><COVID-19><COVID-19 infected patient><COVID-19 patient><COVID-19 positive patient><COVID19 patient><COVID19 positive patient><CV-19><Calorimetry><Cavitas Oris><Cell Body><Cells><Cellular Assay><Chemicals><Chemistry><Clinical><Communicable Diseases><Complementation Test><Coronavirus Infectious Disease 2019><Crystallographies><Crystallography><Cysteine><D pneumoniae><D. pneumoniae><Dehydrogenases><Development><Diplococcus pneumoniae><Drug Targeting><Drugs><E coli><E. coli><Electrons><Ensure><Environment><Enzyme Gene><Enzyme Inhibition><Enzymes><Escherichia coli><Exhibits><Family><Ferredoxin-NADP Reductase><Funding><Gene Expression><Gene Transcription><Generalized Growth><Genes><Genetic Complementation Test><Genetic Transcription><Genome><Genus Mycobacterium><Growth><H influenzae><H. influenzae><Haemophilus influenzae><Half-Cystine><Human><Immune system><Infection><Infectious Disease Pathway><Infectious Diseases><Infectious Disorder><Inorganic Sulfites><Intermediary Metabolism><Iron-Sulfur Protein Reductase><Iron-Sulfur Proteins><Isonicotinic Acid Hydrazide><Kinetics><L-Cysteine><Learning><M catarrhalis><M tb><M tuberculosis><M tuberculosis H37Rv><M. catarrhalis><M. tb><M. tuberculosis><M. tuberculosis H37Rv><Mammalia><Mammals><Measures><Medication><Membrane><Mercaptans><Mercapto Compounds><Metabolic><Metabolic Pathway><Metabolic Processes><Metabolism><Microbe><Miscellaneous Antibiotic><Modern Man><Modern Medicine><Molecular Weight><Moraxella catarrhalis><Mouth><Mycobacterium><Mycobacterium tuberculosis><Mycobacterium tuberculosis H37Rv><NADPH-Ferredoxin Reductase><NIAID><NIGMS><National Institute of Allergy and Infectious Disease><National Institute of General Medical Sciences><Negative Beta Particle><Negatrons><Operon><Oral cavity><Oxidation-Reduction><Oxidative Stress><Oxidoreductase><Oxidoreductase Gene><P aeruginosa><P. aeruginosa><Pathway interactions><Phages><Pharmaceutical Preparations><Plasmids><Play><Pneumococcus><Production><Proteins><Pseudomonas aeruginosa><Pseudomonas pyocyanea><RNA Expression><Recombinants><Redox><Reducing Agents><Reductants><Reductases><Research><Research Resources><Resistance><Resistance to antibiotics><Resistant to antibiotics><Resources><Rifadin><Rifampicin><Rifampin><Rimactane><S element><S pneumoniae><S. pneumoniae><SARS-CoV-2 infected patient><SARS-CoV-2 patient><SARS-CoV-2 positive patient><Series><Source><Specificity><Streptococcal Phages><Streptococcus Bacteriophages><Streptococcus Phages><Streptococcus pneumoniae><Structure><Sulfate><Sulfhydryl Compounds><Sulfides><Sulfites><Sulfur><Sulfur Metabolism><Sulfur Metabolism Pathway><TB drugs><TRX gene><TRX protein><TRX1><TXN gene><Testing><Thiols><Thioredoxin><Tissue Growth><Titrations><Trans Test><Transcription><Translating><Validation><Virulence><Virus><aerobe><aminoacid><anti-TB drugs><anti-bacterial><anti-microbial><anti-tuberculosis drugs><antibiotic drug resistance><antibiotic resistant><antimicrobial><bacteria infection><bacteria metabolism><bacterial disease><bacterial fitness><bacterial metabolism><bacterial virus><bactericidal><bactericide><biological adaptation to stress><biosynthesis><cell assay><cofactor><combat><complement deficiency><complementation analysis><complementation approach><coronavirus disease 2019><coronavirus disease 2019 infected patient><coronavirus disease 2019 patient><coronavirus disease 2019 positive patient><coronavirus disease infected patient><coronavirus disease patient><coronavirus disease positive patient><coronavirus disease-19><coronavirus disease-19 patient><coronavirus infectious disease-19><coronavirus patient><developmental><drug development><drug/agent><electron donor><enzyme mechanism><experiment><experimental research><experimental study><experiments><fighting><fitness><flu infection><flu virus infection><genetic approach><genetic strategy><global gene expression><global health><global transcription profile><human pathogen><improved><in vivo><infected with flu><infected with flu virus><infected with influenza><infected with influenza virus><influenza infection><influenza virus infection><inhibitor><insight><isoniazid><member><membrane structure><meter><microbe pathogen><microbial><microbial pathogen><mtb><mutant><mycobacterial><ontogeny><oxidation reduction reaction><parent grant><pathogen><pathogenic microbe><pathway><patient infected with COVID><patient infected with COVID-19><patient infected with SARS-CoV-2><patient infected with coronavirus disease><patient infected with coronavirus disease 2019><patient infected with severe acute respiratory syndrome coronavirus 2><patient with COVID><patient with COVID-19><patient with COVID19><patient with SARS-CoV-2><patient with coronavirus disease><patient with coronavirus disease 2019><patient with severe acute respiratory distress syndrome coronavirus 2><reaction; crisis><resistant><response><scaffold><scaffolding><severe acute respiratory syndrome coronavirus 2 infected patient><severe acute respiratory syndrome coronavirus 2 patient><severe acute respiratory syndrome coronavirus 2 positive patient><stress response><stress; reaction><sulfhydryl group><transcriptome><tuberculosis drugs><validations>