Mechanistic Insights into β-Lactamase-Catalysed Carbapenem Degradation Through Product Characterisation.

β-Lactamases are a major threat to the clinical use of carbapenems, which are often antibiotics of last resort. Despite this, the reaction outcomes and mechanisms by which β-lactamases degrade carbapenems are still not fully understood. The carbapenem bicyclic core consists of a β-lactam ring fused to a pyrroline ring.

MeLAD: an integrated resource for metalloenzyme-ligand associations.

Motivation: Metalloenzymes are attractive targets for therapeutic intervention owing to their central roles in various biological processes and pathological situations. The fast-growing body of structural data on metalloenzyme-ligand interactions is facilitating efficient drug discovery targeting metalloenzymes. However, there remains a shortage of specific databases that can provide centralized, interconnected information exclusive to metalloenzyme-ligand associations.

Bicyclic Boronate VNRX-5133 Inhibits Metallo- and Serine-β-Lactamases.

The bicyclic boronate VNRX-5133 (taniborbactam) is a new type of β-lactamase inhibitor in clinical development. We report that VNRX-5133 inhibits serine-β-lactamases (SBLs) and some clinically important metallo-β-lactamases (MBLs), including NDM-1 and VIM-1/2. VNRX-5133 activity against IMP-1 and tested B2/B3 MBLs was lower/not observed.

Late-onset ulnar neuritis following treatment of lepromatous leprosy infection.

Neuritis is a frequent complication of Myocobacteria leprae infection and treatment due to the variety of mechanisms through which it can occur. Not only can mycobacterial invasion into peripheral nerves directly cause damage and inflammation, but immune-mediated inflammatory episodes (termed leprosy reactions) can also manifest as neuritis at any point during infection. Treatment of leprosy reactions with thalidomide can also lead to neuritis due to an adverse drug effect.

Molecular Basis of Class A β-Lactamase Inhibition by Relebactam.

β-Lactamase production is the major β-lactam resistance mechanism in Gram-negative bacteria. β-Lactamase inhibitors (BLIs) efficacious against serine β-lactamase (SBL) producers, especially strains carrying the widely disseminated class A enzymes, are required. Relebactam, a diazabicyclooctane (DBO) BLI, is in phase 3 clinical trials in combination with imipenem for the treatment of infections by multidrug-resistant We show that relebactam inhibits five clinically important class A SBLs (despite their differing spectra of activity), representing both chromosomal and plasmid-borne enzymes, i.

Targeting the Mycobacterium tuberculosis transpeptidase Ldt with cysteine-reactive inhibitors including ebselen.

The l,d-transpeptidases (Ldts) are promising antibiotic targets for treating tuberculosis. We report screening of cysteine-reactive inhibitors against LdtMt2 from Mycobacterium tuberculosis. Structural studies on LdtMt2 with potent inhibitor ebselen reveal opening of the benzisoselenazolone ring by a nucleophilic cysteine, forming a complex involving extensive hydrophobic interactions with a substrate-binding loop.

A Fluorescence-Based Assay for Screening β-Lactams Targeting the Mycobacterium tuberculosis Transpeptidase Ldt.

Mycobacterium tuberculosis l,d-transpeptidases (Ldts), which are involved in cell-wall biosynthesis, have emerged as promising targets for the treatment of tuberculosis. However, an efficient method for testing inhibition of these enzymes is not currently available. We present a fluorescence-based assay for Ldt , which is suitable for high-throughput screening.

Expansion of base excision repair compensates for a lack of DNA repair by oxidative dealkylation in budding yeast.

The Mag1 and Tpa1 proteins from budding yeast () have both been reported to repair alkylation damage in DNA. Mag1 initiates the base excision repair pathway by removing alkylated bases from DNA, and Tpa1 has been proposed to directly repair alkylated bases as does the prototypical oxidative dealkylase AlkB from However, we found that repair of methyl methanesulfonate (MMS)-induced alkylation damage in DNA involves Mag1 but not Tpa1. We observed that yeast strains without are no more sensitive to MMS than WT yeast, whereas -deficient yeast are ∼500-fold more sensitive to MMS.

F NMR Monitoring of Reversible Protein Post-Translational Modifications: Class D β-Lactamase Carbamylation and Inhibition.

Bacterial production of β-lactamases with carbapenemase activity is a global health threat. The active sites of class D carbapenemases such as OXA-48, which is of major clinical importance, uniquely contain a carbamylated lysine residue which is essential for catalysis. Although there is significant interest in characterizing this post-translational modification, and it is a promising inhibition target, protein carbamylation is challenging to monitor in solution.

Requirements for improving health and well-being of children with Prader-Willi syndrome and their families.

Prader-Willi syndrome (PWS) is a rare genetic condition with multi-system involvement. The literature was reviewed to describe neurodevelopment and the behavioural phenotype, endocrine and metabolic disorders and respiratory and sleep functioning. Implications for child and family quality of life were explored.

Rapid Identification of Novel Psychoactive and Other Controlled Substances Using Low-Field H NMR Spectroscopy.

An automated approach to the collection of H NMR (nuclear magnetic resonance) spectra using a benchtop NMR spectrometer and the subsequent analysis, processing, and elucidation of components present in seized drug samples are reported. An algorithm is developed to compare spectral data to a reference library of over 300 H NMR spectra, ranking matches by a correlation-based score. A threshold for identification was set at 0.

Profiling interactions of vaborbactam with metallo-β-lactamases.

β-Lactams are the most successful antibacterials, yet their use is threatened by resistance, importantly as caused by β-lactamases. β-Lactamases fall into two mechanistic groups: the serine β-lactamases that utilise a covalent acyl-enzyme mechanism and the metallo β-lactamases that utilise a zinc-bound water nucleophile. Achieving simultaneous inhibition of both β-lactamase classes remains a challenge in the field.

Biocatalytic production of bicyclic β-lactams with three contiguous chiral centres using engineered crotonases.

There is a need to develop asymmetric routes to functionalised β-lactams, which remain the most important group of antibacterials. Here we describe biocatalytic and protein engineering studies concerning carbapenem biosynthesis enzymes, aiming to enable stereoselective production of functionalised carbapenams with three contiguous chiral centres. Structurally-guided substitutions of wildtype carboxymethylproline synthases enable tuning of their C-N and C-C bond forming capacity to produce 5-carboxymethylproline derivatives substituted at C-4 and C-6, from amino acid aldehyde and malonyl-CoA derivatives.

Biochemical and structural investigations clarify the substrate selectivity of the 2-oxoglutarate oxygenase JMJD6.

JmjC domain-containing protein 6 (JMJD6) is a 2-oxoglutarate (2OG)-dependent oxygenase linked to various cellular processes, including splicing regulation, histone modification, transcriptional pause release, hypoxia sensing, and cancer. JMJD6 is reported to catalyze hydroxylation of lysine residue(s) of histones, the tumor-suppressor protein p53, and splicing regulatory proteins, including u2 small nuclear ribonucleoprotein auxiliary factor 65-kDa subunit (U2AF65). JMJD6 is also reported to catalyze -demethylation of -methylated (both mono- and di-methylated) arginine residues of histones and other proteins, including HSP70 (heat-shock protein 70), estrogen receptor α, and RNA helicase A.

Will morphing boron-based inhibitors beat the β-lactamases?

The β-lactams remain the most important antibacterials, but their use is increasingly compromised by resistance, importantly by β-lactamases. Although β-lactam and non-β-lactam inhibitors forming stable acyl-enzyme complexes with nucleophilic serine β-lactamases (SBLs) are widely used, these are increasingly susceptible to evolved SBLs and do not inhibit metallo-β-lactamases (MBLs). Boronic acids and boronate esters, especially cyclic ones, can potently inhibit both SBLs and MBLs.

Does Motivation Impact OCD Symptom Severity? An Exploration of Longitudinal Effects.

Understanding the role of patient motivation in OCD treatment is of clinical importance given the requisite autonomous role of patients in Exposure and Response Prevention. The present study investigated state- and trait-like relations between three variables: two previously established motivational constructs, readiness to change (RTC) and committed action (CA), derived from the University of Rhode Island Change Assessment, and OCD symptom severity as measured by the self-report Yale-Brown Obsessive Compulsive Scale (Y-BOCS-SR). Utilizing a random-intercept cross-lagged panel model (RI-CLPM) design, we assessed autoregressive, within-time correlations, and cross-lagged effects of RTC, CA, and Y-BOCS-SR scores at admission, month 1 of treatment, and discharge from an intensive/residential treatment program for OCD.

Conformational Dynamics Underlies Different Functions of Human KDM7 Histone Demethylases.

The human KDM7 subfamily histone H3 Nϵ-methyl lysine demethylases PHF8 (KDM7B) and KIAA1718 (KDM7A) have different substrate selectivities and are linked to genetic diseases and cancer. We describe experimentally based computational studies revealing that flexibility of the region linking the PHD finger and JmjC domains in PHF8 and KIAA1718 regulates interdomain interactions, the nature of correlated motions, and ultimately H3 binding and demethylation site selectivity. F279S an X-linked mental retardation mutation in PHF8 is involved in correlated motions with the iron ligands and second sphere residues.

A Noninvasive Comparison Study between Human Gliomas with IDH1 and IDH2 Mutations by MR Spectroscopy.

The oncogenes that are expressed in gliomas reprogram particular pathways of glucose, amino acids, and fatty acid metabolism. Mutations in isocitrate dehydrogenase genes (IDH1/2) in diffuse gliomas are associated with abnormally high levels of 2-hydroxyglutarate (2-HG) levels. The aim of this study was to determine whether metabolic reprogramming associated with IDH mutant gliomas leads to additional ¹H MRS-detectable differences between IDH1 and IDH2 mutations, and to identify metabolites correlated with 2-HG.

Structure-Based in Silico Screening Identifies a Potent Ebolavirus Inhibitor from a Traditional Chinese Medicine Library.

Potent Ebolavirus (EBOV) inhibitors will help to curtail outbreaks such as that which occurred in 2014-16 in West Africa. EBOV has on its surface a single glycoprotein (GP) critical for viral entry and membrane fusion. Recent high-resolution complexes of EBOV GP with a variety of approved drugs revealed that binding to a common cavity prevented fusion of the virus and endosomal membranes, inhibiting virus infection.

Persistent Low-level Viremia While on Antiretroviral Therapy Is an Independent Risk Factor for Virologic Failure.

Background: Whether persistent low-level viremia (pLLV) predicts virologic failure (VF) is unclear. We used data from the US Military HIV Natural History Study (NHS), to examine the association of pLLV and VF.

Methods: NHS subjects who initiated combination antiretroviral therapy (ART) after 1996 were included if they had 2 or more VLs measured with a lower limit of detection of ≤50 copies/mL.

Impact of causal explanations for social anxiety disorder on stigma and treatment perceptions.

: There is evidence to suggest that biogenetic explanations for symptoms of mental disorders have become increasingly popular. Research suggests that such explanations provokes mixed blessings: biological explanations may reduce blame but also encourage prognostic pessimism and promote perceptions of pharmacological treatment over psychotherapy. The goal of this study was to evaluate the impact of different causal explanations on social anxiety disorder.

Studies on the inhibition of AmpC and other β-lactamases by cyclic boronates.

Background: The β-lactam antibiotics represent the most successful drug class for treatment of bacterial infections. Resistance to them, importantly via production of β-lactamases, which collectively are able to hydrolyse all classes of β-lactams, threatens their continued widespread use. Bicyclic boronates show potential as broad spectrum inhibitors of the mechanistically distinct serine- (SBL) and metallo- (MBL) β-lactamase families.