A first-in-class inhibitor of Hsp110 molecular chaperones of pathogenic fungi.

Proteins of the Hsp110 family are molecular chaperones that play important roles in protein homeostasis in eukaryotes. The pathogenic fungus Candida albicans, which causes infections in humans, has a single Hsp110, termed Msi3. Here, we provide proof-of-principle evidence supporting fungal Hsp110s as targets for the development of new antifungal drugs.

Merging cultures and disciplines to create a drug discovery ecosystem at Virginia commonwealth university: Medicinal chemistry, structural biology, molecular and behavioral pharmacology and computational chemistry.

The Department of Medicinal Chemistry, together with the Institute for Structural Biology, Drug Discovery and Development, at Virginia Commonwealth University (VCU) has evolved, organically with quite a bit of bootstrapping, into a unique drug discovery ecosystem in response to the environment and culture of the university and the wider research enterprise. Each faculty member that joined the department and/or institute added a layer of expertise, technology and most importantly, innovation, that fertilized numerous collaborations within the University and with outside partners. Despite moderate institutional support with respect to a typical drug discovery enterprise, the VCU drug discovery ecosystem has built and maintained an impressive array of facilities and instrumentation for drug synthesis, drug characterization, biomolecular structural analysis and biophysical analysis, and pharmacological studies.

Phage-Related Ribosomal Proteases (Prps): Discovery, Bioinformatics, and Structural Analysis.

Many new antimicrobials are analogs of existing drugs, sharing the same targets and mechanisms of action. New antibiotic targets are critically needed to combat the growing threat of antimicrobial-resistant bacteria. Phage-related ribosomal proteases (Prps) are a recently structurally characterized antibiotic target found in pathogens such as , , and These bacteria encode an N-terminal extension on their ribosomal protein L27 that is not present in other bacteria.

Phage-Related Ribosomal Protease (Prp) of : In Vitro Michaelis-Menten Kinetics, Screening for Inhibitors, and Crystal Structure of a Covalent Inhibition Product Complex.

Phage-related ribosomal proteases (Prps) are essential for the assembly and maturation of the ribosome in Firmicutes, including the human pathogens , , and . These bacterial proteases cleave off an N-terminal extension of a precursor of ribosomal protein L27, a processing step that is essential for the formation of functional ribosomes. This essential role of Prp in these pathogens has identified this protease as a potential antibiotic target.

The Case against Antibiotics and for Anti-Virulence Therapeutics.

Although antibiotics have been indispensable in the advancement of modern medicine, there are downsides to their use. Growing resistance to broad-spectrum antibiotics is leading to an epidemic of infections untreatable by first-line therapies. Resistance is exacerbated by antibiotics used as growth factors in livestock, over-prescribing by doctors, and poor treatment adherence by patients.

Molecular Targets and Strategies for Inhibition of the Bacterial Type III Secretion System (T3SS); Inhibitors Directly Binding to T3SS Components.

The type III secretion system (T3SS) is a virulence apparatus used by many Gram-negative pathogenic bacteria to cause infections. Pathogens utilizing a T3SS are responsible for millions of infections yearly. Since many T3SS knockout strains are incapable of causing systemic infection, the T3SS has emerged as an attractive anti-virulence target for therapeutic design.

Fluorescence Detection of Type III Secretion Using a Glu-CyFur Reporter System in .

Enteropathogenic (EPEC) is a major cause of infantile diarrhea worldwide. EPEC and the closely related murine model of EPEC infection, , utilize a type III secretion system (T3SS) to propagate the infection. Since the T3SS is not essential for the bacteria to survive or propagate, inhibiting the virulence factor with a therapeutic would treat the infection without causing harm to commensal bacteria.

Antibodies Inhibiting the Type III Secretion System of Gram-Negative Pathogenic Bacteria.

Pathogenic bacteria are a global health threat, with over 2 million infections caused by Gram-negative bacteria every year in the United States. This problem is exacerbated by the increase in resistance to common antibiotics that are routinely used to treat these infections, creating an urgent need for innovative ways to treat and prevent virulence caused by these pathogens. Many Gram-negative pathogenic bacteria use a type III secretion system (T3SS) to inject toxins and other effector proteins directly into host cells.

Delivery of Heterologous Proteins, Enzymes, and Antigens via the Bacterial Type III Secretion System.

The Type III Secretion System (T3SS) is a multimeric protein complex composed of over 20 different proteins, utilized by Gram-negative bacteria to infect eukaryotic host cells. The T3SS has been implicated as a virulence factor by which pathogens cause infection and has recently been characterized as a communication tool between bacteria and plant cells in the rhizosphere. The T3SS has been repurposed to be used as a tool for the delivery of non-native or heterologous proteins to eukaryotic cells or the extracellular space for a variety of purposes, including drug discovery and drug delivery.

Animal Models of Type III Secretion System-Mediated Pathogenesis.

The type III secretion system (T3SS) is a conserved virulence factor used by many Gram-negative pathogenic bacteria and has become an important target for anti-virulence drugs. Most T3SS inhibitors to date have been discovered using in vitro screening assays. Pharmacokinetics and other important characteristics of pharmaceuticals cannot be determined with in vitro assays alone.

Natural Product Type III Secretion System Inhibitors.

Many known inhibitors of the bacterial type III secretion system (T3SS), a virulence factor used by pathogenic bacteria to infect host cells, are natural products. These compounds, produced by bacteria, fungi, and plants, may have developed as prophylactic treatments for potential attack by bacterial pathogens or as an attempt by symbiotic organisms to protect their hosts. Regardless, better understanding of the structures and mechanisms of action of these compounds may open opportunities for drug development against diseases caused by pathogens utilizing the T3SS.

Molecular insights into the biosynthesis of guadinomine: a type III secretion system inhibitor.

Guadinomines are a recently discovered family of anti-infective compounds produced by Streptomyces sp. K01-0509 with a novel mode of action. With an IC(50) of 14 nM, guadinomine B is the most potent known inhibitor of the type III secretion system (TTSS) of Gram-negative bacteria.

Total synthesis of (-)-callipeltoside A.

A total synthesis of (-)-callipeltoside A (1) has been achieved. The core macrocycle was made via a dual macrolactonization/pyran hemiketal formation reaction, developed to circumvent issues related to the reversible nature of acylketene formation from β-keto lactone substrates. Initial approaches to the core of the natural product that revolved around ring-closing metathesis (RCM) and relay ring-closing metathesis (RRCM) reactions are also described.

Room temperature acylketene formation? 1,3-Dioxin-4-ones via silver(I) activation of phenylthioacetoacetate in the presence of ketones.

Silver(I) activation of thioacetoacetates in the presence of ketones produces 1,3-dioxin-4-ones. Mechanistic studies addressing the intermediacy of an acylketene intermediate are described.

A Useful Modification of the Evans Magnesium Halide-Catalyzed -Aldol Reaction: Application to Enolizable Aldehydes.

A practical protocol for use of the magnesium halide-catalyzed -aldol reaction of an Evans -acyloxazolidinone with enolizable aldehydes is reported. The yields of -aldol adducts for saturated or unsaturated and branched or unbranched aliphatic aldehydes are preparatively useful.

Dual macrolactonization/pyran-hemiketal formation via acylketenes: applications to the synthesis of (-)-callipeltoside A and a lyngbyaloside B model system.

[Image: see text] Thermal generation of acylketenes in diol-containing substrates results in dual macrocyclization/pyran-hemiketal formation. This transformation expands the scope of acylketene macrolactonizations and their application to the synthesis of complex macrolides. Triol and even tetrol substrates also have been closed in highly regioselective fashion.

Decarboxylative isomerization of N-Acyl-2-oxazolidinones to 2-oxazolines.

N-Acyl-2-oxazolidinones are ring-opened by lithium iodide and decarboxylated in the presence of a mild proton source. Further reaction with an amine base provides 2-oxazolines. The transformation is general for oxazolidinones unsubstituted in the 5 position and occurs under mild conditions (25-50 degrees C).