Selective measurement of NAPE-PLD activity via a PLA-resistant fluorogenic N-acyl-phosphatidylethanolamine analog.

N-acyl-phosphatidylethanolamine (NAPE)-hydrolyzing phospholipase D (NAPE-PLD) is a zinc metallohydrolase enzyme that converts NAPEs to bioactive N-acyl-ethanolamides. Altered NAPE-PLD activity may contribute to pathogenesis of obesity, diabetes, atherosclerosis, and neurological diseases. Selective measurement of NAPE-PLD activity is challenging, however, because of alternative phospholipase pathways for NAPE hydrolysis.

Simultaneous Exposure to Intracellular and Extracellular Photosensitizers for the Treatment of Staphylococcus aureus Infections.

Staphylococcus aureus is a serious threat to public health due to the rise of antibiotic resistance in this organism, which can prolong or exacerbate skin and soft tissue infections (SSTIs). Methicillin-resistant S. aureus is a Gram-positive bacterium and a leading cause of SSTIs.

Ten-Year Retrospective of the Vanderbilt Institute of Chemical Biology Chemical Synthesis Core.

Chemical synthesis has been described as a central science. Its practice provides access to the chemical structures of known and/or designed function. In particular, human health is greatly impacted by synthesis that enables advancements in both basic science discoveries in chemical biology as well as translational research that can lead to new therapeutics.

Synthesis of the Siderophore Coelichelin and Its Utility as a Probe in the Study of Bacterial Metal Sensing and Response.

A convergent total synthesis of the siderophore coelichelin is described. The synthetic route also provided access to acetyl coelichelin and other congeners of the parent siderophore. The synthetic products were evaluated for their ability to bind ferric iron and promote growth of a siderophore-deficient strain of the Gram-negative bacterium Pseudomonas aeruginosa under iron restriction conditions.

Rhodol-based thallium sensors for cellular imaging of potassium channel activity.

Thallium (Tl+) flux assays enable imaging of potassium (K+) channel activity in cells and tissues by exploiting the permeability of K+ channels to Tl+ coupled with a fluorescent Tl+ sensitive dye. Common Tl+ sensing dyes utilize fluorescein as the fluorophore though fluorescein exhibits certain undesirable properties in these assays including short excitation wavelengths and pH sensitivity. To overcome these drawbacks, the replacement of fluorescein with rhodols was investigated.

Antibacterial photosensitization through activation of coproporphyrinogen oxidase.

Gram-positive bacteria cause the majority of skin and soft tissue infections (SSTIs), resulting in the most common reason for clinic visits in the United States. Recently, it was discovered that Gram-positive pathogens use a unique heme biosynthesis pathway, which implicates this pathway as a target for development of antibacterial therapies. We report here the identification of a small-molecule activator of coproporphyrinogen oxidase (CgoX) from Gram-positive bacteria, an enzyme essential for heme biosynthesis.

A Small-Molecule Inhibitor of Iron-Sulfur Cluster Assembly Uncovers a Link between Virulence Regulation and Metabolism in Staphylococcus aureus.

The rising problem of antimicrobial resistance in Staphylococcus aureus necessitates the discovery of novel therapeutic targets for small-molecule intervention. A major obstacle of drug discovery is identifying the target of molecules selected from high-throughput phenotypic assays. Here, we show that the toxicity of a small molecule termed '882 is dependent on the constitutive activity of the S.

Bacterial Nitric Oxide Synthase Is Required for the Staphylococcus aureus Response to Heme Stress.

Staphylococcus aureus is a pathogen that causes significant morbidity and mortality worldwide. Within the vertebrate host, S. aureus requires heme as a nutrient iron source and as a cofactor for multiple cellular processes.

Decoupling Activation of Heme Biosynthesis from Anaerobic Toxicity in a Molecule Active in Staphylococcus aureus.

Small molecules active in the pathogenic bacterium Staphylococcus aureus are valuable tools for the study of its basic biology and pathogenesis, and many molecules may provide leads for novel therapeutics. We have previously reported a small molecule, 1, which activates endogenous heme biosynthesis in S. aureus, leading to an accumulation of intracellular heme.

Two-component system cross-regulation integrates Bacillus anthracis response to heme and cell envelope stress.

Two-component signaling systems (TCSs) are one of the mechanisms that bacteria employ to sense and adapt to changes in the environment. A prototypical TCS functions as a phosphorelay from a membrane-bound sensor histidine kinase (HK) to a cytoplasmic response regulator (RR) that controls target gene expression. Despite significant homology in the signaling domains of HKs and RRs, TCSs are thought to typically function as linear systems with little to no cross-talk between non-cognate HK-RR pairs.

Activation of heme biosynthesis by a small molecule that is toxic to fermenting Staphylococcus aureus.

Staphylococcus aureus is a significant infectious threat to global public health. Acquisition or synthesis of heme is required for S. aureus to capture energy through respiration, but an excess of this critical cofactor is toxic to bacteria.