Understanding the dynamics of membrane protein-ligand interactions within a native lipid bilayer is a major goal for drug discovery. Typically, cell-based assays are used, however, they are often blind to the effects of protein modifications. In this study, using the archetypal G protein-coupled receptor rhodopsin, we found that the receptor and its effectors can be released directly from retina rod disc membranes using infrared irradiation in a mass spectrometer.
View Article and Find Full Text PDFDNA methylation is a crucial epigenetic modification used as a biomarker for early cancer progression. However, existing methods for DNA methylation analysis are complex, time-consuming, and prone to DNA degradation. This work demonstrates selective capture of unmethylated DNAs using ZnO nanowires without chemical or biological modifications, thereby concentrating methylated DNA, particularly those with high methylation levels that can predict cancer risk.
View Article and Find Full Text PDFIntroduction: Precocious puberty (PP), which is sometimes divided into gonadotropin-dependent or gonadotropin-independent PP, is a pathological condition characterized by premature secretion of gonadal steroids resulting in the early development of secondary sexual characteristics. Girls younger than 6 years with idiopathic gonadotropin-dependent PP (referred to as central PP or CPP) who receive gonadotropin-releasing hormone analog (GnRHa) therapy experience an increase in their adult height (AH) in contrast to girls who are aged 6 years or more, who show no consistent pattern of increase even with GnRHa therapy.
Methods: In total, 133 girls aged 6 years or more who visited any one of the seven study centers between April 2000 and March 2020 and who met the diagnostic criteria for PP in Japan were retrospectively examined.
Modern conservative dentistry is taking the lead in daily clinical practice and is relying on adhesion. Whether it is a simple composite, ceramic inlays, onlays, veneers or crowns, the common factor for a successful outcome is a good bonding of these elements to dental structures. Thus, the purpose of this study was to evaluate the bond strength of resin composite to dentin when using a new device, the DENTIPURE KM™ (KM, Beirut, Lebanon), which provides a pure air flow, free of any contaminants and without humidity, when compared to other dental equipment.
View Article and Find Full Text PDFIn this systematic review, we aimed to assess the current evidence regarding the effectiveness of functional treatment with both removable and fixed appliances to normalize the external soft tissue for skeletal class II adolescent individuals. We performed a broad electronic search to retrieve relevant studies from nine databases to identify randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that investigated soft tissue changes following functional treatment and evaluated the changes using 2D lateral cephalometric radiographs and 3D-optical surface laser scanning. A total of three RCTs and eight CCTs were included.
View Article and Find Full Text PDFWe report the first sequencing of morpholino antisense oligonucleotides (phosphorodiamidate morpholino oligomers, PMOs) using electron capture dissociation (ECD) mass spectrometry. In this research, we found dissociation of the backbone of 18- to 25-mer PMOs to produce d and z ions as the major ions, and 100% cleavage coverage (sequence coverage) was obtained with these ions. This is a critical contrast with beam-type collision-induced dissociation, which dominantly induces base loss, so it is difficult to obtain sequence information.
View Article and Find Full Text PDFThe progression of precancerous lesions to malignancy is often accompanied by increasing complexity of chromosomal alterations but how these alterations arise is poorly understood. Here we perform haplotype-specific analysis of chromosomal copy-number evolution in the progression of Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC) on multiregional whole-genome sequencing data of BE with dysplasia and microscopic EAC foci. We identify distinct patterns of copy-number evolution indicating multigenerational chromosomal instability that is initiated by cell division errors but propagated only after p53 loss.
View Article and Find Full Text PDFSubjecting a physical system to extreme conditions is one of the means often used to obtain a better understanding and deeper insight into its organization and structure. In the case of the atomic nucleus, one such approach is to investigate isotopes that have very different neutron-to-proton (N/Z) ratios than in stable nuclei. Light, neutron-rich isotopes exhibit the most asymmetric N/Z ratios and those lying beyond the limits of binding, which undergo spontaneous neutron emission and exist only as very short-lived resonances (about 10 s), provide the most stringent tests of modern nuclear-structure theories.
View Article and Find Full Text PDFNative mass spectrometry has recently moved alongside traditional structural biology techniques in its ability to provide clear insights into the composition of protein complexes. However, to date, limited software tools are available for the comprehensive analysis of native mass spectrometry data on protein complexes, particularly for experiments aimed at elucidating the composition of an intact protein complex. Here, we introduce ProSight Native as a start-to-finish informatics platform for analyzing native protein and protein complex data.
View Article and Find Full Text PDFThe detection of starlight from the host galaxies of quasars during the reionization epoch (z > 6) has been elusive, even with deep Hubble Space Telescope observations. The current highest redshift quasar host detected, at z = 4.5, required the magnifying effect of a foreground lensing galaxy.
View Article and Find Full Text PDFMembrane proteins are challenging to analyze by native mass spectrometry (MS) as their hydrophobic nature typically requires stabilization in detergent micelles that are removed prior to analysis via collisional activation. There is however a practical limit to the amount of energy which can be applied, which often precludes subsequent characterization by top-down MS. To overcome this barrier, we have applied a modified Orbitrap Eclipse Tribrid mass spectrometer coupled to an infrared laser within a high-pressure linear ion trap.
View Article and Find Full Text PDFAppropriate modulation of escape behaviors in response to potentially damaging stimuli is essential for survival. Although nociceptive circuitry has been studied, it is poorly understood how genetic contexts affect relevant escape responses. Using an unbiased genome-wide association analysis, we identified an Ly6/α-neurotoxin family protein, Belly roll (Bero), which negatively regulates nociceptive escape behavior.
View Article and Find Full Text PDFUnlabelled: The safety, efficacy, and cost-effectiveness of Infliximab biosimilar agents in the management of inflammatory bowel disease in adults have been shown. These agents have been recommended for pediatric inflammatory bowel disease, and although institutions are initiating therapy with the biosimilar agents (IFX-B), few are switching maintenance therapy from the originator (IFX-O). The aim was to compare biochemical markers of disease activity of children with inflammatory bowel disease on maintenance therapy with IFX-B to their previous markers on IFX-O.
View Article and Find Full Text PDFNo studies have directly compared postoperative umbilical port site (UPS)-related complications between transumbilical and periumbilical incisions (TUI and PUI) after laparoscopic surgery in children. We conducted a retrospective review of 324 children of ≤15 years of age who underwent laparoscopic repair (LR) for inguinal hernia, via either a TUI or PUI, between 2010 and 2020. UPS-related complications, such as wound infection and umbilical deformity, were compared between TUI and PUI.
View Article and Find Full Text PDFInteractions between the SARS-CoV-2 Spike protein and ACE2 are one of the most scrutinized reactions of our time. Yet, questions remain as to the impact of glycans on mediating ACE2 dimerization and downstream interactions with Spike. Here, we address these unanswered questions by combining a glycoengineering strategy with high-resolution native mass spectrometry (MS) to investigate the impact of -glycan occupancy on the assembly of multiple Spike-ACE2 complexes.
View Article and Find Full Text PDFThe main protease from SARS-CoV-2 (M) is responsible for cleavage of the viral polyprotein. M self-processing is called maturation, and it is crucial for enzyme dimerization and activity. Here we use C145S M to study the structure and dynamics of N-terminal cleavage in solution.
View Article and Find Full Text PDFNucleosome dynamics, such as nucleosome sliding and DNA unwrapping, are important for gene regulation in eukaryotic chromatin. H2A.Z, a variant of histone H2A that is highly evolutionarily conserved, participates in gene regulation by forming unstable multipositioned nucleosomes and .
View Article and Find Full Text PDFThe β-delayed one- and two-neutron emission probabilities (P_{1n} and P_{2n}) of 20 neutron-rich nuclei with N≥82 have been measured at the RIBF facility of the RIKEN Nishina Center. P_{1n} of ^{130,131}Ag, ^{133,134}Cd, ^{135,136}In, and ^{138,139}Sn were determined for the first time, and stringent upper limits were placed on P_{2n} for nearly all cases. β-delayed two-neutron emission (β2n) was unambiguously identified in ^{133}Cd and ^{135,136}In, and their P_{2n} were measured.
View Article and Find Full Text PDFIntroduction: Due to the predominantly cellular immunosuppression, infections are frequent in chronic dialysis patients, in particular tuberculosis (TB). The main objective of our study is to evaluate tuberculosis healthcare delay in dialysis patients and to raise the diagnostic challenge in these patients.
Material And Methods: The study is retrospective and multicenter including tuberculosis cases of chronic dialysis patients either in hemodialysis (HD) or peritoneal dialysis (PD) in the central region of Morocco during a 10-year period between 2012 and 2021.
We report on the dissociation of singly protonated peptides by electrons using electron-activated dissociation (EAD), which comprises electron impact excitation of ions from organics (EIEIO), electronic-excitation dissociation (EED), and electron ionization dissociation (EIoD). Various singly protonated peptides were dissociated using a recently reported fast EAD device. The dissociation can be induced through two pathways: (i) vibrational dissociation similar to collision-activated dissociation (CAD, or collision-induced dissociation, CID) by relaxation from a molecular electronic excited state to high vibrational states; and (ii) radical-induced dissociation where molecular electronic excitation is followed by homolytic cleavage.
View Article and Find Full Text PDFChannelling of glucose via glycogen, known as the glycogen shunt, may play an important role in the metabolism of brain tumours, especially in hypoxic conditions. We aimed to dissect the role of glycogen degradation in glioblastoma (GBM) response to ionising radiation (IR). Knockdown of the glycogen phosphorylase liver isoform (PYGL), but not the brain isoform (PYGB), decreased clonogenic growth and survival of GBM cell lines and sensitised them to IR doses of 10-12 Gy.
View Article and Find Full Text PDFWe investigated the antitumor effects of oleanolic acid (OA) and ursolic acid (UA) on adult T-cell leukemia cells. OA and UA dose-dependently inhibited the proliferation of adult T-cell leukemia cells. UA-treated cells showed caspase 3/7 and caspase 9 activation.
View Article and Find Full Text PDFSarcomeric contraction in cardiomyocytes serves as the basis for the heart's pump functions. It has generally been considered that in cardiac muscle as well as in skeletal muscle, sarcomeres equally contribute to myofibrillar dynamics in myocytes at varying loads by producing similar levels of active and passive force. In the present study, we expressed α-actinin-AcGFP in Z-disks to analyze dynamic behaviors of sequentially connected individual sarcomeres along a myofibril in a left ventricular (LV) myocyte of the in vivo beating mouse heart.
View Article and Find Full Text PDFBacteria often secrete diffusible protein toxins (bacteriocins) to kill bystander cells during interbacterial competition. Here, we use biochemical, biophysical and structural analyses to show how a bacteriocin exploits TolC, a major outer-membrane antibiotic efflux channel in Gram-negative bacteria, to transport itself across the outer membrane of target cells. Klebicin C (KlebC), a rRNase toxin produced by Klebsiella pneumoniae, binds TolC of a related species (K.
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