Effects of deforestation on multitaxa community similarity in the Brazilian Atlantic Forest.

Habitat loss can lead to biotic homogenization (decrease in β diversity) or differentiation (increase in β diversity) of biological communities. However, it is unclear which of these ecological processes predominates in human-modified landscapes. We used data on vertebrates, invertebrates, and plants to quantify β diversity based on species occurrence and abundance among communities in 1367 landscapes with varying amounts of habitat (<30%, 30-60%, or >60% of forest cover) throughout the Brazilian Atlantic Forest.

Binding of a single nitric oxide molecule is sufficient to disrupt DNA binding of the nitrosative stress regulator NsrR.

The regulatory protein NsrR, a member of the Rrf2 protein superfamily, plays a major role in the cellular response to nitrosative stress in many benign and pathogenic bacteria. The homodimeric protein binds a [4Fe-4S] cluster in each subunit (termed holo NsrR), and represses transcription of genes primarily involved in NO detoxification. Holo NsrR reacts rapidly with multiple NO molecules per [4Fe-4S] cluster, a complex reaction, with loss of DNA binding and formation of NsrR-bound iron-nitrosyl species.

CyaY and TusA regulate ISC- and SUF-mediated l-cysteine desulfurase activity.

CyaY, the frataxin homolog of , plays an important role in ISC iron-sulfur cluster assembly through interactions with the cysteine desulfurase IscS, which regulate the supply of sulfur. IscS is not exclusive for ISC Fe-S cluster assembly, as it functions as a hub for the supply of sulfur to a number of other sulfur-requiring pathways, such as for the biosynthesis of Moco and thiolated tRNAs. How the balance of sulfur supply to the various competing pathways is achieved is not fully understood, but a network of protein-protein interactions plays a key role.

Shallow conductance decay along the array of a single tetraheme protein wire.

Multiheme cytochromes (MHCs) are the building blocks of highly conductive micrometre-long supramolecular wires found in so-called electrical bacteria. Recent studies have revealed that these proteins possess a long supramolecular array of closely packed cofactors along the main molecular axis alternating between perpendicular and stacking configurations (TST = T-shaped, stacked, T-shaped). While TST arrays have been identified as the likely electron conduit, the mechanisms of outstanding long-range charge transport observed in these structures remain unknown.

Engineering of bespoke photosensitiser-microbe interfaces for enhanced semi-artificial photosynthesis.

Biohybrid systems for solar fuel production integrate artificial light-harvesting materials with biological catalysts such as microbes. In this perspective, we discuss the rational design of the abiotic-biotic interface in biohybrid systems by reviewing microbes and synthetic light-harvesting materials, as well as presenting various approaches to coupling these two components together. To maximise performance and scalability of such semi-artificial systems, we emphasise that the interfacial design requires consideration of two important aspects: attachment and electron transfer.

Targeted photodynamic therapy for breast cancer: the potential of glyconanoparticles.

Photodynamic therapy (PDT) uses a non-toxic light sensitive molecule, a photosensitiser, that releases cytotoxic reactive oxygen species upon activation with light of a specific wavelength. Here, glycan-modified 16 nm gold nanoparticles (glycoAuNPs) were explored for their use in targeted PDT, where the photosensitiser was localised to the target cell through selective glycan-lectin interactions. Polyacrylamide (PAA)-glycans were chosen to assess glycan binding to the cell lines.

Stabilisation of the RirA [4Fe-4S] cluster results in loss of iron-sensing function.

RirA is a global iron regulator in diverse that belongs to the Rrf2 superfamily of transcriptional regulators, which can contain an iron-sulfur (Fe-S) cluster. Under iron-replete conditions, RirA contains a [4Fe-4S] cluster, enabling high-affinity binding to RirA-regulated operator sequences, thereby causing the repression of cellular iron uptake. Under iron deficiency, one of the cluster irons dissociates, generating an unstable [3Fe-4S] form that subsequently degrades to a [2Fe-2S] form and then to apo RirA, resulting in loss of high-affinity DNA-binding.

Correction: Thiamine analogues as inhibitors of pyruvate dehydrogenase and discovery of a thiamine analogue with non-thiamine related antiplasmodial activity.

[This corrects the article DOI: 10.1039/D2MD00085G.].

Native mass spectrometric studies of IscSU reveal a concerted, sulfur-initiated mechanism of iron-sulfur cluster assembly.

Iron-sulfur (Fe-S) clusters are cofactors essential for life. Though the proteins that function in the assembly of Fe-S clusters are well known, details of the molecular mechanism are less well established. The Isc (iron-sulfur cluster) biogenesis apparatus is widespread in bacteria and is the closest homologue to the human system.

Photocatalytic Removal of the Greenhouse Gas Nitrous Oxide by Liposomal Microreactors.

Nitrous oxide (NO) is a potent greenhouse and ozone-reactive gas for which emissions are growing rapidly due to increasingly intensive agriculture. Synthetic catalysts for NO decomposition typically contain precious metals and/or operate at elevated temperatures driving a desire for more sustainable alternatives. Here we demonstrate self-assembly of liposomal microreactors enabling catalytic reduction of NO to the climate neutral product N.

Thiamine analogues as inhibitors of pyruvate dehydrogenase and discovery of a thiamine analogue with non-thiamine related antiplasmodial activity.

A series of derivatives of a triazole analogue of thiamine has been synthesised. When tested as inhibitors of porcine pyruvate dehydrogenase, the benzoyl ester derivatives proved to be potent thiamine pyrophosphate (TPP) competitive inhibitors, with the affinity of the most potent analogue ( = 54 nM) almost matching the affinity of TPP itself. When tested as antiplasmodials, most of the derivatives showed modest activity (IC value >60 μM), except for a 4'--benzyl derivative, which has an IC value in the low micromolar range.

Exploring the therapeutic mechanisms of in diabetes mellitus through network pharmacology, molecular docking and molecular dynamics.

is reported as anti-diabetic medicinal plant and is also used as an ethnomedicine. However, its mode of action as an anti-diabetic agent has not been clearly elucidated. Hence, the present study investigated the probable mechanism of action of to manage diabetes mellitus network pharmacology and molecular docking and simulations studies.

NleB/SseK-catalyzed arginine-glycosylation and enteropathogen virulence are finely tuned by a single variable position contiguous to the catalytic machinery.

NleB/SseK effectors are arginine-GlcNAc-transferases expressed by enteric bacterial pathogens that modify host cell proteins to disrupt signaling pathways. While the conserved NleB and NleB1 proteins display a broad selectivity towards host proteins, SseK1, SseK2, and SseK3 have a narrowed protein substrate selectivity. Here, by combining computational and biophysical experiments, we demonstrate that the broad protein substrate selectivity of NleB relies on Tyr284, a second-shell residue contiguous to the catalytic machinery.

Molecular Recognition of Natural and Non-Natural Substrates by Cellodextrin Phosphorylase from Ruminiclostridium Thermocellum Investigated by NMR Spectroscopy.

β-1→4-Glucan polysaccharides like cellulose, derivatives and analogues, are attracting attention due to their unique physicochemical properties, as ideal candidates for many different applications in biotechnology. Access to these polysaccharides with a high level of purity at scale is still challenging, and eco-friendly alternatives by using enzymes in vitro are highly desirable. One prominent candidate enzyme is cellodextrin phosphorylase (CDP) from Ruminiclostridium thermocellum, which is able to yield cellulose oligomers from short cellodextrins and α-d-glucose 1-phosphate (Glc-1-P) as substrates.

Nutrition and Frailty: Opportunities for Prevention and Treatment.

Frailty is a syndrome of growing importance given the global ageing population. While frailty is a multifactorial process, poor nutritional status is considered a key contributor to its pathophysiology. As nutrition is a modifiable risk factor for frailty, strategies to prevent and treat frailty should consider dietary change.

Repeated exposure of nosocomial pathogens to silver does not select for silver resistance but does impact ciprofloxacin susceptibility.

The rise of antimicrobial resistant bacteria coupled with a void in antibiotic development marks Antimicrobial Resistance as one of the biggest current threats to modern medicine. Antimicrobial metals are being developed and used as alternative anti-infectives, however, the existence of known resistance mechanisms and limited data regarding bacterial responses to long-term metal exposure are barriers to widespread implementation. In this study, a panel of reference and clinical strains of major nosocomial pathogens were subjected to serial dosage cycles of silver and ciprofloxacin.

Peptide directed phthalocyanine-gold nanoparticles for selective photodynamic therapy of EGFR overexpressing cancers.

Gold nanoparticles, covalently functionalised with the photosensitiser C11Pc and PEG, were actively targeted towards epidermal growth factor receptor overexpressing cancers using the peptide FITC-βAAEYLRK. Selective phototoxicity was observed at nanomolar concentrations with minimal dark toxicity.

Proposing a causal pathway for health-related quality of life in people with psychotic disorders.

This study aimed to establish independent predictors for health-related quality of life (HRQoL) in people with psychotic disorders, and the mediating role of global functioning in those relationships. Data for 1642 people collected as part of the second Australian National Survey of Psychosis were analyzed. The Assessment of Quality of Life (AQoL)-4D and the Personal and Social Performance scale were used for assessing HRQoL and global functioning respectively.

The effectiveness of mammography surveillance after treatment of primary breast cancer: A single centre retrospective cohort study.

Introduction: There is a little evidence that routine follow-up of patients treated for early breast cancer (BC) to detect ibsilateral breast tumour recurrence (IBTR), or contralateral breast cancer (CBC), is either effective or offers any mortality benefits. We report our experience of following patients with early BC for recurrences and new primaries in order to determine the role of mammogram surveillance.

Methods: Single centre, retrospective primary observational study was designed.

Iron Oxidation in Bacterioferritin Ferroxidase Centre, a Site Designed to React Rapidly with HO but Slowly with O.

Both O and HO can oxidize iron at the ferroxidase center (FC) of bacterioferritin (EcBfr) but mechanistic details of the two reactions need clarification. UV/Vis, EPR, and Mössbauer spectroscopies have been used to follow the reactions when apo-EcBfr, pre-loaded anaerobically with Fe, was exposed to O or HO. We show that O binds di-Fe FC reversibly, two Fe ions are oxidized in concert and a HO molecule is formed and released to the solution.

Electron Transfer from Haem to the Di-Iron Ferroxidase Centre in Bacterioferritin.

The iron redox cycle in ferritins is not completely understood. Bacterioferritins are distinct from other ferritins in that they contain haem groups. It is acknowledged that the two iron motifs in bacterioferritins, the di-nuclear ferroxidase centre and the haem B group, play key roles in two opposing processes, iron sequestration and iron mobilisation, respectively, and the two redox processes are independent.

Combination of system biology to probe the anti-viral activity of andrographolide and its derivative against COVID-19.

The present study aimed to investigate the binding affinity of andrographolide and its derivative 14-deoxy-11,12-didehydroandrographolide with targets related to COVID-19 and their probable role in regulating multiple pathways in COVID-19 infection. SMILES of both compounds were retrieved from the PubChem database and predicted for probably regulated proteins. The predicted proteins were queried in STRING to evaluate the protein-protein interaction, and modulated pathways were identified concerning the KEGG database.

Three cheers for nitrogen: aza-DKPs, the aza analogues of 2,5-diketopiperazines.

Nitrogen-containing heterocycles represent a major source of pharmacological probes and drug candidates. To extend their molecular diversity and their potential biological activities, it is of importance to design and synthesize new N-heterocyclic scaffolds. Therefore, aza-diketopiperazines (aza-DKPs), the aza analogues of well-known 2,5-diketopiperazines (DKPs), emerged as a promising new scaffold.

Climate action requires new accounting guidance and governance frameworks to manage carbon in shelf seas.

Accounting guidelines exist for the recording of carbon flows in terrestrial and coastal ecosystems. Shelf sea sediments, while considered an important carbon store, have yet to receive comparable scrutiny. Here, we explore whether effective management of carbon stocks accumulating in shelf seas could contribute towards a nation's greenhouse gas emissions reduction targets.