Acid Cleavable Biotin-Alkyne Improves Sensitivity for Direct Detection of Biotin Labeled Peptides in Biorthogonal Noncanonical Amino Acid Tagging Analysis.

Biorthogonal noncanonical amino acid tagging is a labeling strategy that covalently adds a biotin-alkyne (BA) to methionine analogs via a click reaction. When methionine analogs are incorporated into a proteome, enrichment of the BA-labeled proteins allows the detection of newly synthesized proteins (NSP) by mass spectrometry. We previously reported that our direct detection of biotin-containing tags strategy increased protein identifications by enriching for BA-peptides instead of BA-proteins.

Repeat modules and N-linked glycans define structure and antigenicity of a critical enterotoxigenic E. coli adhesin.

Enterotoxigenic Escherichia coli (ETEC) cause hundreds of millions of cases of infectious diarrhea annually, predominantly in children from low-middle income regions. Notably, in children, as well as volunteers challenged with ETEC, diarrheal severity is significantly increased in blood group A (bgA) individuals. EtpA, is a secreted glycoprotein adhesin that functions as a blood group A lectin to promote critical interactions between ETEC and blood group A glycans on intestinal epithelia for effective bacterial adhesion and toxin delivery.

Repeat modules and N-linked glycans define structure and antigenicity of a critical enterotoxigenic .

Enterotoxigenic (ETEC) cause hundreds of millions of cases of infectious diarrhea annually, predominantly in children from low-middle income regions. Notably, in children, as well as human volunteers challenged with ETEC, diarrheal severity is significantly increased severity in blood group A (bgA) individuals. EtpA, is a secreted glycoprotein adhesin that functions as a blood group A lectin to promote critical interactions between ETEC and blood group A glycans on intestinal epithelia for effective bacterial adhesion and toxin delivery.

Effects of (2R,6R)-hydroxynorketamine in assays of acute pain-stimulated and pain-depressed behaviors in mice.

Ketamine has been shown to produce analgesia in various acute and chronic pain states; however, abuse liability concerns have limited its utility. The ketamine metabolite (2R,6R)-hydroxynorketamine (HNK) has been shown to produce antidepressant-like effects similar to ketamine without abuse liability concerns. (2R,6R)-HNK produces sustained analgesia in models of chronic pain, but has yet to be evaluated in models of acute pain.

Native top-down proteomics reveals EGFR-ERα signaling crosstalk in breast cancer cells dissociates NUTF2 dimers to modulate ERα signaling and cell growth.

Oligomerization of proteins and their modified forms (proteoforms) produces functional protein complexes . Complexoforms are complexes that consist of the same set of proteins with different proteoforms . The ability to characterize these assemblies within cells is critical to understanding the molecular mechanisms involved in disease and to designing effective drugs.

Optimizing spinal cord injury in zebrafish larvae: effects of age on the injury response.

Zebrafish are an increasingly popular model to study spinal cord injury (SCI) regeneration. The transparency of larval zebrafish makes them ideal to study cellular processes in real time. Standardized approaches, including age of injury, are not readily available making comparisons of the results with other models challenging.

Evolving spike-protein -glycosylation in SARS-CoV-2 variants.

Since >3 years, SARS-CoV-2 has plunged humans into a colossal pandemic. Henceforth, multiple waves of infection have swept through the human population, led by variants that were able to partially evade acquired immunity. The co-evolution of SARS-CoV-2 variants with human immunity provides an excellent opportunity to study the interaction between viral pathogens and their human hosts.

IL-6R/Signal Transducer and Activator of Transcription 3 Signaling in Keratinocytes rather than in T Cells Induces Psoriasis-Like Dermatitis in Mice.

Signal transducer and activator of transcription 3 (STAT3) is important for psoriasis pathogenesis because STAT3 signaling downstream of IL-6, IL-21, IL-22, and IL-23 contributes to T helper type 17 cell development and because transgenic mice with keratinocyte (KC) STAT3 expression (K14-Stat3C mice) develop psoriasis-like dermatitis. In this study, the relative contribution of STAT3 signaling in KCs versus in T cells was evaluated in the imiquimod model of psoriasis-like dermatitis. Mice with STAT3-inducible deletion in KCs (K5-Stat3 mice) had decreased psoriasis-like dermatitis and epidermal STAT3 phosphorylation compared with wild-type mice, whereas mice with constitutive deletion of STAT3 in all T cells were similar to wild-type mice.

Acyl Peptide Enzyme Hydrolase (APEH) activity is inhibited by lipid metabolites and peroxidation products.

Acyl Peptide Enzyme Hydrolase (APEH) activity is decreased in certain diseases but the mechanism and impact behind this loss in activity is not well understood. We hypothesized that lipid metabolites and lipid peroxidation products produced in inflammatory diseases may bind to and inhibit APEH activity. In vitro studies carried out in mammalian cell lysates, as well as with purified APEH protein, support our hypothesis that cellular lipid metabolites and lipid peroxidation products significantly decrease APEH activity.

Pan-caspase inhibition as a potential host-directed immunotherapy against MRSA and other bacterial skin infections.

causes most skin infections in humans, and the emergence of methicillin-resistant (MRSA) strains is a serious public health threat. There is an urgent clinical need for nonantibiotic immunotherapies to treat MRSA infections and prevent the spread of antibiotic resistance. Here, we investigated the pan-caspase inhibitor quinoline-valine-aspartic acid-difluorophenoxymethyl ketone (Q-VD-OPH) for efficacy against MRSA skin infection in mice.

Nicotine-free vapor inhalation produces behavioral disruptions and anxiety-like behaviors in mice: Effects of puff duration, session length, sex, and flavor.

Electronic-cigarette's (ECIGs) popularity has grown over the last decade and changed the way individuals administer nicotine. Preclinical research is imperative for understanding the addictive properties and health-risks associated with ECIG use; however, there is not a standard dosing regimen used across research laboratories. The main objective was to determine how vapor puff durations, administration session length, and flavored e-liquid alter general and mood-disorder related behaviors while providing a foundation of vapor administration parameters.

Epicutaneous Staphylococcus aureus induces IL-36 to enhance IgE production and ensuing allergic disease.

IgE induced by type 2 immune responses in atopic dermatitis is implicated in the progression of atopic dermatitis to other allergic diseases, including food allergies, allergic rhinitis, and asthma. However, the keratinocyte-derived signals that promote IgE and ensuing allergic diseases remain unclear. Herein, in a mouse model of atopic dermatitis-like skin inflammation induced by epicutaneous Staphylococcus aureus exposure, keratinocyte release of IL‑36α along with IL-4 triggered B cell IgE class-switching, plasma cell differentiation, and increased serum IgE levels-all of which were abrogated in IL-36R-deficient mice or anti-IL‑36R-blocking antibody-treated mice.

Which Way Do We Go? Complex Interactions in Atopic Dermatitis Pathogenesis.

Atopic dermatitis (AD) is a common, chronic, inflammatory skin condition characterized by recurrent and pruritic skin eruptions. Multiple factors contribute to the pathogenesis of AD, including skin barrier dysfunction, microbial dysbiosis, and immune dysregulation. Interactions among these factors form a complex, multidirectional network that can reinforce atopic skin disease but can also be ameliorated by targeted therapies.

Assessment of the rapid and sustained antidepressant-like effects of dextromethorphan in mice.

The glutamatergic system has emerged as a novel pathway for treating major depressive disorder (MDD) with the focus on producing both rapid and sustained antidepressant effects. Dextromethorphan is a noncompetitive N-methyl-d-aspartate (NMDA) receptor antagonist that has produced antidepressant-like effects in forced swim and tail suspension tests (TST); however, the rapid and sustained antidepressant-like effects of dextromethorphan have not been evaluated. This study evaluated the rapid and sustained (24 h) antidepressant-like effects of dextromethorphan (0-32 mg/kg) in C56BL/6 mice using the novelty-induced hypophagia (NIH) test and TST, respectively.

Repeated nicotine vapor inhalation induces behavioral sensitization in male and female C57BL/6 mice.

Electronic cigarette use has significantly increased over the past decade. However, there is limited preclinical research on the behavioral and abuse-related effects of nicotine vapor inhalation in rodents. The present study evaluates the effects of repeated nicotine vapor inhalation in male and female mice using a nicotine behavioral sensitization model.

N-heterocyclic carbene-functionalized magic-number gold nanoclusters.

Magic-number gold nanoclusters are atomically precise nanomaterials that have enabled unprecedented insight into structure-property relationships in nanoscience. Thiolates are the most common ligand, binding to the cluster via a staple motif in which only central gold atoms are in the metallic state. The lack of other strongly bound ligands for nanoclusters with different bonding modes has been a significant limitation in the field.

Second-generation IL-2 receptor-targeted diphtheria fusion toxin exhibits antitumor activity and synergy with anti-PD-1 in melanoma.

Denileukin diftitox (DAB-IL-2, Ontak) is a diphtheria-toxin-based fusion protein that depletes CD25-positive cells including regulatory T cells and has been approved for the treatment of persistent or recurrent cutaneous T cell lymphoma. However, the clinical use of denileukin diftitox was limited by vascular leak toxicity and production issues related to drug aggregation and purity. We found that a single amino acid substitution (V6A) in a motif associated with vascular leak induction yields a fully active, second-generation biologic, s-DAB-IL-2(V6A), which elicits 50-fold less human umbilical vein endothelial cell monolayer permeation and is 3.

Mechanistic Basis for ATP-Dependent Inhibition of Glutamine Synthetase by Tabtoxinine-β-lactam.

Tabtoxinine-β-lactam (TβL), also known as wildfire toxin, is a time- and ATP-dependent inhibitor of glutamine synthetase produced by plant pathogenic strains of Pseudomonas syringae. Here we demonstrate that recombinant glutamine synthetase from Escherichia coli phosphorylates the C3-hydroxyl group of the TβL 3-(S)-hydroxy-β-lactam (3-HβL) warhead. Phosphorylation of TβL generates a stable, noncovalent enzyme-ADP-inhibitor complex that resembles the glutamine synthetase tetrahedral transition state.

Structure and dynamics of surfactant interfaces in organically modified clays.

Organic modification of clays with surfactants is required for the preparation of polymer-clay nanocomposites for a variety of applications. We have studied the structure and dynamics of interfaces in synthetic clays modified with phosphonium surfactants. The chemical shifts, line widths, and relaxation times measured by 31P, 13C, and 1H NMR and the relaxation times measured by impedance spectroscopy allow us to monitor the dynamics over a wide range of time scales.

Dynamics of alkyl ammonium intercalants within organically modified montmorillonite: Dielectric relaxation and ionic conductivity.

The low-frequency (0.01 Hz-10 MHz) dynamic characteristics of alkyl quaternary ammonium exchanged montmorillonite (SC20A) were investigated to determine the correlation between temperature-dependent changes in the interlayer structure and collective mobility of the surfactant. From 25 to 165 degrees C, SC20A exhibits two interlayer transitions, one ascribed to the melting of the intercalated alkyl chains of the surfactant (20-40 degrees C) and another associated with an abrupt decrease in the interlayer's coefficient of thermal expansion (100 degrees C).

Assessment of vascular calcification in ESRD patients using spiral CT.

Background: Dialysis patients have increased vascular calcification of the coronary arteries and aorta by electron beam CT scan. The purpose of the present study was to utilize an alternative machine, spiral CT, to assess calcification in end-stage renal disease (ESRD) patients.

Methods: Two groups of patients with ESRD were evaluated: group 1, those receiving a renal transplant (n=38); and group 2, those remaining on dialysis (n=33).