A Versatile Virus-Mimetic Engineering Approach for Concurrent Protein Nanocage Surface-Functionalization and Cargo Encapsulation.

Naturally occurring protein nanocages like ferritin are self-assembled from multiple subunits. Because of their unique cage-like structure and biocompatibility, there is a growing interest in their biomedical use. A multipurpose and straightforward engineering approach does not exist for using nanocages to make drug-delivery systems by encapsulating hydrophilic or hydrophobic drugs and developing vaccines by surface functionalization with a protein like an antigen.

Radical -Adenosyl-l-Methionine Enzyme PylB: A C-Centered Radical to Convert l-Lysine into (3)-3-Methyl-d-Ornithine.

PylB is a radical -adenosyl-l-methionine (SAM) enzyme predicted to convert l-lysine into (3)-3-methyl-d-ornithine, a precursor in the biosynthesis of the 22nd proteogenic amino acid pyrrolysine. This protein highly resembles that of the radical SAM tyrosine and tryptophan lyases, which activate their substrate by abstracting a H atom from the amino-nitrogen position. Here, combining assays, analytical methods, electron paramagnetic resonance spectroscopy, and theoretical methods, we demonstrated that instead, PylB activates its substrate by abstracting a H atom from the Cγ position of l-lysine to afford the radical-based β-scission.

Maturation of the [FeFe]-Hydrogenase: Direct Transfer of the (κ -cysteinate)Fe (CN)(CO) Complex B from HydG to HydE.

[FeFe]-hydrogenases efficiently catalyze the reversible oxidation of molecular hydrogen. Their prowess stems from the intricate H-cluster, combining a [Fe S ] center with a binuclear iron center ([2Fe] ). In the latter, each iron atom is coordinated by a CO and CN ligand, connected by a CO and an azadithiolate ligand.

Model-Based Analysis of the Influence of Alcohol Use and Age on Pharmacokinetics-Pharmacodynamics of Oral Oxycodone in Middle-Age and Older Community-Dwelling Adults.

Little is known about how opioid responses vary by age and in the presence of alcohol consumption. This model-based pharmacokinetic (PK)-pharmacodynamic (PD) analysis quantified the impact of age and alcohol use on pupillometry and cold pressor test (CPT) PD based on data from an open-label study of a single, immediate-release 10-mg oral oxycodone in middle-age and older adults (aged 35-85) without severe functional limitations. PK and pupillometry assessments were obtained on 11 occasions over 8 hours.

Oxygen-Sensitive Metalloprotein Structure Determination by Cryo-Electron Microscopy.

Metalloproteins are involved in key cell processes such as photosynthesis, respiration, and oxygen transport. However, the presence of transition metals (notably iron as a component of [Fe-S] clusters) often makes these proteins sensitive to oxygen-induced degradation. Consequently, their study usually requires strict anaerobic conditions.

Radical SAM Enzymes and Metallocofactor Assembly: A Structural Point of View.

This Review focuses on the structure-function relationship of radical -adenosyl-l-methionine (SAM) enzymes involved in the assembly of metallocofactors corresponding to the active sites of [FeFe]-hydrogenase and nitrogenase [MoFe]-protein. It does not claim to correspond to an extensive review on the assembly machineries of these enzyme active sites, for which many good reviews are already available, but instead deals with the contribution of structural data to the understanding of their chemical mechanism (Buren et al. Chem.

Elevated customary alcohol consumption attenuates opioid effects.

Background: Regular alcohol consumption is on the rise among older adults and has the potential of altering the subjective experience of pain and response to pain medications. This study examined the cognitive, analgesic and side effect response to oxycodone in middle age and older adults with elevated levels of customary alcohol consumption in a human laboratory setting.

Methods: After refraining from alcohol for one day, eligible participants underwent baseline assessment cognition and side effects by means of questionnaires that were repeated at three time points (90 min, 5 and 8 h) following administration of a 10 mg oral dose of oxycodone.

Cognitive skill training improves memory, function, and use of cognitive strategies in cancer survivors.

Background: Cancer survivors commonly report symptoms of impaired cognition. This project examined effectiveness of a behavioral skills training intervention to improve cognition and reduce cognitive dysfunction symptoms in cancer survivors.

Methods: Participants were randomly assigned to group-based workshops focused on learning new cognitive skills (skills treatment-TX) or an active control of education workshops (education control-EC) or a passive control of wait list (WL).

An unexpected P-cluster like intermediate to the nitrogenase FeMo-co.

The nitrogenase MoFe protein contains two different FeS centers, the P-cluster and the iron-molybdenum cofactor (FeMo-co). The former is a [FeS] center responsible for conveying electrons to the latter, a [MoFeSC-()-homocitrate] species, where N reduction takes place. NifB is arguably the key enzyme in FeMo-co assembly as it catalyzes the fusion of two [FeS] clusters and the insertion of carbide and sulfide ions to build NifB-co, a [FeSC] precursor to FeMo-co.

T cells regulate lymph node-resident ILC populations in a tissue and subset-specific way.

Innate lymphoid cells (ILCs) have been shown to be significantly affected in the small intestine lamina propria and secondary lymphoid organs (SLOs) of conventional lymphopenic mice. How ILCs are regulated by adaptive immunity in SLOs remains unclear. In T cell-deficient mice, ILC2s are significantly increased in the mesenteric lymph nodes (MLNs) at the expense of CCR6 ILC3s, which are nonetheless increased in the peripheral lymph nodes (PLNs).

Phospholipase D inhibitors screening: Probing and evaluation of ancient and novel molecules.

Phospholipase D (PLD) is a ubiquitous enzyme that cleaves the distal phosphoester bond of phospholipids generating phosphatidic acid (PA). In plants, PA is involved in numerous cell responses triggered by stress. Similarly, in mammals, PA is also a second messenger involved in tumorigenesis.

Relationship of Phosphatidylethanol Biomarker to Self-Reported Alcohol Drinking Patterns in Older and Middle-Age Adults.

Background: Risky alcohol consumption is on the rise among older adults. Biomarkers such as phosphatidylethanol (PEth) have been used to evaluate the correspondence between an objective, laboratory-based biomarker and self-report of alcohol consumption. This study examined the relationship between PEth, self-report of alcohol consumption, and health indices in a sample of community-dwelling older to middle-age adults (aged 35 to 89) with healthy and risky levels of alcohol consumption.

The interplay between innate lymphoid cells and T cells.

ILCs and T cells are closely related functionally but they significantly differ in their ability to circulate, expand, and renew. Cooperation and reciprocal functional regulation suggest that these cell types are more complementary than simply redundant during immune responses. How ILCs shape T-cell responses is strongly dependent on the tissue and inflammatory context.

Scratching Beneath the Surface: Linking Skin Pathology with Food Allergy.

A link between atopic dermatitis and food allergy has long been suspected but remains elusive. In this issue, Leyva-Castillo et al. (2019) show how mechanical injury of the skin initiates a cascade of events that stimulate the expansion of mucosal mast cells and promote food anaphylaxis.

Impact of androgen deprivation therapy on mood, cognition, and risk for AD.

Prostate cancer is the most common form of cancer diagnosed in men. Androgen deprivation therapy (ADT) is commonly prescribed, with some estimates indicating over 50% of men with prostate cancer receive ADT at some point in their treatment. Men on ADT are typically otherwise healthy, with good long-term survival.

Crystallographic evidence for unexpected selective tyrosine hydroxylations in an aerated achiral Ru-papain conjugate.

The X-ray structure of an aerated achiral Ru-papain conjugate has revealed the hydroxylation of two tyrosine residues found near the ruthenium ion. The most likely mechanism involves a ruthenium-bound superoxide as the reactive species responsible for the first hydroxylation and the resulting high valent Ru(iv)[double bond, length as m-dash]O species for the second one.

Expression and Purification of Recombinant Vigna unguiculata Phospholipase D in Pichia pastoris for Structural Studies.

The production of pure enzymes in high quantities is a proven strategy to study the catalytic mechanism as well as the solving of structure at the atomic scale for therapeutic or industrial purposes. Phospholipase D (PLD, EC 3.1.

Changes in cerebral metabolic activity in men undergoing androgen deprivation therapy for non-metastatic prostate cancer.

Objective: Androgen deprivation therapy (ADT) is a common treatment option for men with biochemical relapse from prostate cancer. ADT is associated with changes in mood, cognition, and quality of life, and most recently with increased risk for Alzheimer's disease (AD). This study examined changes in brain metabolism using positron emission tomography (PET) in men undergoing intermittent ADT.

The NOX Family of Proteins Is Also Present in Bacteria.

Transmembrane NADPH oxidase (NOX) enzymes have been so far only characterized in eukaryotes. In most of these organisms, they reduce molecular oxygen to superoxide and, depending on the presence of additional domains, are called NOX or dual oxidases (DUOX). Reactive oxygen species (ROS), including superoxide, have been traditionally considered accidental toxic by-products of aerobic metabolism.

Molecular dissection of protein-protein interactions between integrin α5β1 and the Helicobacter pylori Cag type IV secretion system.

The more severe strains of the bacterial human pathogen Helicobacter pylori produce a type IV secretion system (cagT4SS) to inject the oncoprotein cytotoxin-associated gene A (CagA) into gastric cells. This syringe-like molecular apparatus is prolonged by an external pilus that exploits integrins as receptors to mediate the injection of CagA. The molecular determinants of the interaction of the cagT4SS pilus with the integrin ectodomain are still poorly understood.

Effect of simvastatin on CSF Alzheimer disease biomarkers in cognitively normal adults.

Objective: To examine potential disease-modifying effects of statin drugs, we conducted a 12-month randomized, placebo-controlled clinical trial of simvastatin in cognitively normal adults using change in CSF Alzheimer disease biomarkers as primary outcome measure.

Methods: Participants were 45-64 years old and statin-naive with normal cognition and normal or mildly elevated cholesterol. Forty-six participants completed the 1-year study per protocol (25 in the simvastatin and 21 in the placebo group).

Dementia and co-occurring chronic conditions: a systematic literature review to identify what is known and where are the gaps in the evidence?

Objective: The challenges posed by people living with multiple chronic conditions are unique for people with dementia and other significant cognitive impairment. There have been recent calls to action to review the existing literature on co-occurring chronic conditions and dementia in order to better understand the effect of cognitive impairment on disease management, mobility, and mortality.

Methods: This systematic literature review searched PubMed databases through 2011 (updated in 2016) using key constructs of older adults, moderate-to-severe cognitive impairment (both diagnosed and undiagnosed dementia), and chronic conditions.

Tetramerization and interdomain flexibility of the replication initiation controller YabA enables simultaneous binding to multiple partners.

YabA negatively regulates initiation of DNA replication in low-GC Gram-positive bacteria. The protein exerts its control through interactions with the initiator protein DnaA and the sliding clamp DnaN. Here, we combined X-ray crystallography, X-ray scattering (SAXS), modeling and biophysical approaches, with in vivo experimental data to gain insight into YabA function.

Structure and primase-mediated activation of a bacterial dodecameric replicative helicase.

Replicative helicases are essential ATPases that unwind DNA to initiate chromosomal replication. While bacterial replicative DnaB helicases are hexameric, Helicobacter pylori DnaB (HpDnaB) was found to form double hexamers, similar to some archaeal and eukaryotic replicative helicases. Here we present a structural and functional analysis of HpDnaB protein during primosome formation.