FtsZ and PBP4 bind to the conformationally dynamic N-terminal domain of GpsB.

In the Firmicutes phylum, GpsB is a membrane associated protein that coordinates peptidoglycan synthesis with cell growth and division. Although GpsB has been studied in several bacteria, the structure, function, and interactome of GpsB is largely uncharacterized. To address this knowledge gap, we solved the crystal structure of the N-terminal domain of GpsB, which adopts an atypical, asymmetric dimer, and demonstrates major conformational flexibility that can be mapped to a hinge region formed by a three-residue insertion exclusive to .

Development of the Safe and Broad-Spectrum Aldehyde and Ketoamide Mpro inhibitors Derived from the Constrained α, γ-AA Peptide Scaffold.

SARS-CoV-2 is still wreaking havoc all over the world with surging morbidity and high mortality. The main protease (M ) is essential in the replication of SARS-CoV-2, enabling itself an active target for antiviral development. Herein, we reported the design and synthesis of a new class of peptidomimetics-constrained α, γ-AA peptides, based on which a series of aldehyde and ketoamide inhibitors of the M of SARS-CoV-2 were prepared.

A unique class of Zn-binding serine-based PBPs underlies cephalosporin resistance and sporogenesis in Clostridioides difficile.

Treatment with β-lactam antibiotics, particularly cephalosporins, is a major risk factor for Clostridioides difficile infection. These broad-spectrum antibiotics irreversibly inhibit penicillin-binding proteins (PBPs), which are serine-based enzymes that assemble the bacterial cell wall. However, C.

Structure-Based Ligand Design Targeting LpxA in Lipid A Biosynthesis.

Enzymes involved in lipid A biosynthesis are promising antibacterial drug targets in Gram-negative bacteria. In this study, we use a structure-based design approach to develop a series of novel tetrazole ligands with low μM affinity for LpxA, the first enzyme in the lipid A pathway. Aided by previous structural data, X-ray crystallography, and surface plasmon resonance bioanalysis, we identify 17 hit compounds.

GpsB Coordinates Cell Division and Cell Surface Decoration by Wall Teichoic Acids in Staphylococcus aureus.

Bacterial cell division is a complex and highly regulated process requiring the coordination of many different proteins. Despite substantial work in model organisms, our understanding of the systems regulating cell division in noncanonical organisms, including critical human pathogens, is far from complete. One such organism is Staphylococcus aureus, a spherical bacterium that lacks known cell division regulatory proteins.

Discovery of Di- and Trihaloacetamides as Covalent SARS-CoV-2 Main Protease Inhibitors with High Target Specificity.

The main protease (M) is a validated antiviral drug target of SARS-CoV-2. A number of M inhibitors have now advanced to animal model study and human clinical trials. However, one issue yet to be addressed is the target selectivity over host proteases such as cathepsin L.

Discovery of SARS-CoV-2 Papain-like Protease Inhibitors through a Combination of High-Throughput Screening and a FlipGFP-Based Reporter Assay.

The papain-like protease (PL) of SARS-CoV-2 is a validated antiviral drug target. Through a fluorescence resonance energy transfer-based high-throughput screening and subsequent lead optimization, we identified several PL inhibitors including and with improved enzymatic inhibition and antiviral activity compared to , which was reported as a SARS-CoV PL inhibitor. Significantly, we developed a cell-based FlipGFP assay that can be applied to predict the cellular antiviral activity of PL inhibitors in the BSL-2 setting.

Expedited Approach toward the Rational Design of Noncovalent SARS-CoV-2 Main Protease Inhibitors.

The main protease (M) of SARS-CoV-2 is a validated antiviral drug target. Several M inhibitors have been reported with potent enzymatic inhibition and cellular antiviral activity, including , , , and , with each containing a reactive warhead that covalently modifies the catalytic Cys145. Coupling structure-based drug design with the one-pot Ugi four-component reaction, we discovered one of the most potent noncovalent inhibitors, () that is structurally distinct from the canonical M inhibitor .

Discovery of SARS-CoV-2 papain-like protease inhibitors through a combination of high-throughput screening and FlipGFP-based reporter assay.

The papain-like protease (PL ) of SARS-CoV-2 is a validated antiviral drug target. PL is involved in the cleavage of viral polyproteins and antagonizing host innate immune response through its deubiquitinating and deISG15ylating activities, rendering it a high profile antiviral drug target. Through a FRET-based high-throughput screening, several hits were identified as PL inhibitors with IC values at the single-digit micromolar range.

N-Hydroxyformamide LpxC inhibitors, their in vivo efficacy in a mouse Escherichia coli infection model, and their safety in a rat hemodynamic assay.

UDP-3-O-(R-3-hydroxyacyl)-N-acetylglucosamine deacetylase (LpxC), the zinc metalloenzyme catalyzing the first committed step of lipid A biosynthesis in Gram-negative bacteria, has been a target for antibacterial drug discovery for many years. All inhibitor chemotypes reaching an advanced preclinical stage and clinical phase 1 have contained terminal hydroxamic acid, and none have been successfully advanced due, in part, to safety concerns, including hemodynamic effects. We hypothesized that the safety of LpxC inhibitors could be improved by replacing the terminal hydroxamic acid with a different zinc-binding group.

Structure and inhibition of the SARS-CoV-2 main protease reveal strategy for developing dual inhibitors against M and cathepsin L.

The main protease (M) of SARS-CoV-2 is a key antiviral drug target. While most M inhibitors have a γ-lactam glutamine surrogate at the P1 position, we recently found that several M inhibitors have hydrophobic moieties at the P1 site, including calpain inhibitors II and XII, which are also active against human cathepsin L, a host protease that is important for viral entry. In this study, we solved x-ray crystal structures of M in complex with calpain inhibitors II and XII and three analogs of The structure of M with calpain inhibitor II confirmed that the S1 pocket can accommodate a hydrophobic methionine side chain, challenging the idea that a hydrophilic residue is necessary at this position.

Structure and inhibition of the SARS-CoV-2 main protease reveals strategy for developing dual inhibitors against M and cathepsin L.

The main protease (M) of SARS-CoV-2, the pathogen responsible for the COVID-19 pandemic, is a key antiviral drug target. While most SARS-CoV-2 M inhibitors have a γ-lactam glutamine surrogate at the P1 position, we recently discovered several M inhibitors have hydrophobic moieties at the P1 site, including calpain inhibitors II/XII, which are also active against human cathepsin L, a host-protease that is important for viral entry. To determine the binding mode of these calpain inhibitors and establish a structure-activity relationship, we solved X-ray crystal structures of M in complex with calpain inhibitors II and XII, and three analogues of , one of the most potent M inhibitors .

Interdependent YpsA- and YfhS-Mediated Cell Division and Cell Size Phenotypes in .

Although many bacterial cell division factors have been uncovered over the years, evidence from recent studies points to the existence of yet-to-be-discovered factors involved in cell division regulation. Thus, it is important to identify factors and conditions that regulate cell division to obtain a better understanding of this fundamental biological process. We recently reported that in the Gram-positive organisms and , increased production of YpsA resulted in cell division inhibition.

Discovery of an Orally Available Diazabicyclooctane Inhibitor (ETX0282) of Class A, C, and D Serine β-Lactamases.

Multidrug resistant Gram-negative bacterial infections are an increasing public health threat due to rapidly rising resistance toward β-lactam antibiotics. The hydrolytic enzymes called β-lactamases are responsible for a large proportion of the resistance phenotype. β-Lactamase inhibitors (BLIs) can be administered in combination with β-lactam antibiotics to negate the action of the β-lactamases, thereby restoring activity of the β-lactam.

Boceprevir, GC-376, and calpain inhibitors II, XII inhibit SARS-CoV-2 viral replication by targeting the viral main protease.

A new coronavirus SARS-CoV-2, also called novel coronavirus 2019 (2019-nCoV), started to circulate among humans around December 2019, and it is now widespread as a global pandemic. The disease caused by SARS-CoV-2 virus is called COVID-19, which is highly contagious and has an overall mortality rate of 6.35% as of May 26, 2020.

Boceprevir, GC-376, and calpain inhibitors II, XII inhibit SARS-CoV-2 viral replication by targeting the viral main protease.

A novel coronavirus SARS-CoV-2, also called novel coronavirus 2019 (nCoV-19), started to circulate among humans around December 2019, and it is now widespread as a global pandemic. The disease caused by SARS-CoV-2 virus is called COVID-19, which is highly contagious and has an overall mortality rate of 6.96% as of May 4, 2020.

Influence of the α-Methoxy Group on the Reaction of Temocillin with Pseudomonas aeruginosa PBP3 and CTX-M-14 β-Lactamase.

The prevalence of multidrug-resistant has led to the reexamination of older "forgotten" drugs, such as temocillin, for their ability to combat resistant microbes. Temocillin is the 6-α-methoxy analogue of ticarcillin, a carboxypenicillin with well-characterized antipseudomonal properties. The α-methoxy modification confers resistance to serine β-lactamases, yet temocillin is ineffective against growth.

Discovery of dual-activity small-molecule ligands of Pseudomonas aeruginosa LpxA and LpxD using SPR and X-ray crystallography.

The lipid A biosynthesis pathway is essential in Pseudomonas aeruginosa. LpxA and LpxD are the first and third enzymes in this pathway respectively, and are regarded as promising antibiotic targets. The unique structural similarities between these two enzymes make them suitable targets for dual-binding inhibitors, a characteristic that would decrease the likelihood of mutational resistance and increase cell-based activity.