A hydrothermal method-grown, Fe-doped ZnO crystal, was excited by the XFEL prototype at Spring-8 facility. The scintillation signal exhibited <;10-ps rise time and <;100-ps decay time; making it the ...fastest scintillator for XFEL timing studies.
B cell lymphoma 6 (BCL6) is a transcriptional repressor that interacts with its corepressors BcoR and SMRT. Since this protein-protein interaction (PPI) induces activation and differentiation of B ...lymphocytes, BCL6 has been an attractive drug target for potential autoimmune disease treatments. Here we report a novel BCL6 inhibitory peptide, F1324 (Ac-LWYTDIRMSWRVP-OH), which we discovered using phage display technology; we also discuss this peptide's structure-activity relationship (SAR). For BCL6(5-129) binding, KD and IC50 values of F1324 were 0.57 nM and 1 nM according to the results of an SPR analysis and cell-free ELISA assay, respectively. In contrast, BcoR(Arg498-514Pro) and SMRT(Leu1422-Arg1438) exhibited relatively weak micromole-order binding to BCL6. Furthermore, Fusion protein AcGFP-F1324 transiently expressed in HEK293T cells inhibited intracellular PPI in cell-based M2H assay. By examination of the truncation and fragmentation of F1324, the C-terminal sequence WRVP, which is similar to the BcoR(509-512) sequence WVVP, was identified as being critical for BCL6 binding. In addition, subsequent single-crystal X-ray diffraction analysis of F1324/BCL6(5-129) complex revealed that the high affinity of F1324 was caused by effective interaction of its side chains while its main chain structure was similar to that of BcoR(Arg498-514Pro). To our knowledge, F1324 is the strongest BCL6-binding peptide yet reported.
•F1324 was discovered as 5000-times higher affinity peptide to BCL6 than that of BcoR(R498-P514).•X-ray crystal structure analysis revealed the binding mode.•To our knowledge, F1324 is the strongest BCL6-binding and -inhibition peptide so far.
Bacterial iron-sulfur (Fe–S) clusters are essential cofactors for many metabolic pathways, and Fe–S cluster-containing proteins (Fe–S proteins) regulate the expression of various important genes. ...However, biosynthesis of such clusters has remained unknown in genus Burkholderia. Here, we clarified that Burkholderia multivorans ATCC 17616 relies on the ISC system for the biosynthesis of Fe–S clusters, and that the biosynthetic genes are organized as an isc operon, whose first gene encodes IscR, a transcriptional regulatory Fe–S protein. Transcription of the isc operon was repressed and activated under iron-rich and -limiting conditions, respectively, and Fur, an iron-responsive global transcriptional regulator, was indicated to indirectly regulate the expression of isc operon. Further analysis using a ΔiscR mutant in combination with a constitutive expression system of IscR and its derivatives indicated transcriptional repression and activation of isc operon by holo- and apo-forms of IscR, respectively, through their binding to the sequences within an isc promoter-containing (Pisc) fragment. Biochemical analysis using the Pisc fragment suggested that the apo-IscR binding sequence differs from the holo-IscR binding sequence. The results obtained in this study revealed a unique regulatory system for the expression of the ATCC 17616 isc operon that has not been observed in other genera.
•Pore structure of cement paste and mortar analyzed after high-speed impact tests.•Pore structure of cement paste was coarsened when the moisture content was high.•Pore structure of mortar was ...coarsened regardless of moisture content.•Mechanism of coarsening of pore structure due to collision was proposed.
In some numerical simulations of collisions on concrete, the densification of the pore structure has been assumed to be attributed to collisions. However, a previous experimental study conducted by the authors revealed that the pore structure can be coarsened by impact. The conditions of this coarsening have not yet been clarified. In this study, impact tests were conducted on cementitious materials with and without sand, admixture materials, and with different moisture contents, to understand the influences of these factors on the cracking, pore structure, and compositional changes caused by impacts. In the water-saturated cement paste specimens, mercury intrusion porosimetry showed that the pore structure of the region near the impact point was coarsened. Conversely, the pore structure of the cement paste specimens with low-water content was densified. In the mortar, the pore structure was coarsened in both the saturated and dried specimens. To explain the mechanism of incurred pore structure changes due to collision, mechanical and thermal effects were proposed. These include compaction due to mechanical action, the expansion force generated by liquid-water pressure upon impact, and vapor pressure changes due to heat, respectively. The study’s findings improve our understanding of the responses of cementitious materials subjected to impact loads and allow us to obtain more accurate damage estimations. The findings revealed the necessity of the investigation on the cause of the high-stiffness response at impact other than compaction. If the liquid or vapor pressure caused the pore coarsening at impact, it may be reduced by the effective release of these pressures.
Antibodies are used for many therapeutic and biotechnological purposes. Because the affinity of an antibody to the antigen is critical for clinical efficacy of pharmaceuticals, many affinity ...maturation strategies have been developed. Although we previously reported an affinity maturation strategy in which the association rate of the antibody toward its antigen is improved by introducing a cluster of arginine residues into the framework region of the antibody, the detailed molecular mechanism responsible for this improvement has been unknown. In this study, we introduced five arginine residues into an anti‐hen egg white lysozyme antibody (HyHEL10) Fab fragment to create the R5‐mutant and comprehensively characterized the interaction between antibody and antigen using thermodynamic analysis, X‐ray crystallography, and molecular dynamics (MD) simulations. Our results indicate that introduction of charged residues strongly enhanced the association rate, as previously reported, and the antibody–antigen complex structure was almost the same for the R5‐mutant and wild‐type Fabs. The MD simulations indicate that the mutation increased conformational diversity in complementarity‐determining region loops and thereby enhanced the association rate. These observations provide the molecular basis of affinity maturation by R5 mutation.
PDB Code(s): 8GQ1;
Small-cell lung carcinoma (SCLC) and large-cell neuroendocrine lung carcinoma (LCNEC) are high-grade lung neuroendocrine tumors (NET). However, comparative protein expression within SCLC and LCNEC ...remains unclear. Here, protein expression profiles were obtained via mass spectrometry-based proteomic analysis. Weighted gene co-expression network analysis (WGCNA) identified co-expressed modules and hub genes. Of 34 identified modules, six were significant and selected for protein-protein interaction (PPI) network analysis and pathway enrichment. Within the six modules, the activation of cellular processes and complexes, such as alternative mRNA splicing, translation initiation, nucleosome remodeling and deacetylase (NuRD) complex, SWItch/Sucrose Non-Fermentable (SWI/SNF) superfamily-type complex, chromatin remodeling pathway, and mRNA metabolic processes, were significant to SCLC. Modules enriched in processes, including signal recognition particle (SRP)-dependent co-translational protein targeting to membrane, nuclear-transcribed mRNA catabolic process of nonsense-mediated decay (NMD), and cellular macromolecule catabolic process, were characteristically activated in LCNEC. Novel high-degree hub genes were identified for each module. Master and upstream regulators were predicted via causal network analysis. This study provides an understanding of the molecular differences in tumorigenesis and malignancy between SCLC and LCNEC and may help identify potential therapeutic targets.
Acidovorax sp. KKS102 is a beta-proteobacterium capable of degrading polychlorinated biphenyls (PCBs). In this study, we examined its growth in liquid nutrient broth supplemented with different ...carbon sources. KKS102 had at least 3 distinct metabolic phases designated as metabolic phases 1-3, with phase 2 having 2 sub-phases. For example, succinate, fumarate, and glutamate, known to repress the PCB/biphenyl catabolic operon in KKS102, were utilized in phase 1, while acetate, arabinose, and glycerol in phase 2, and glucose and mannose in phase 3. We also showed that the BphQ response regulator mediating catabolite control in KKS102, whose expression level increased moderately through the growth, plays important roles in carbon metabolism in phases 2 and 3. Our study elucidates the hierarchical growth of KKS102 in nutrient-rich media. This insight is crucial for studies exploiting microbial biodegradation capabilities and advancing studies for catabolite regulation mechanisms.
We report the case of a 2‐month‐old infant who was found moribund in her crib. Postmortem computed tomography (PMCT) was performed before autopsy. As the baby had a severe subdural hematoma, retinal ...hemorrhage, and encephalopathy on PMCT, abusive head trauma (AHT) was tentatively diagnosed. At autopsy, no scalp hemorrhages or skull fractures were found; however, the classic triad of AHT was present, mainly on the right side. Additionally, there was dark red discoloration around the heart, and the liver, spleen, and pancreas were enlarged. Peripheral blood was macroscopically cloudy with marked leukocytosis. After careful histological examination, B‐cell precursor acute lymphoblastic leukemia (ALL) was diagnosed. All the macroscopic lesions could be attributed to ALL. The manner of death was natural. To the best of our knowledge, this is the first report of infantile ALL mimicking AHT on PMCT images. This case demonstrates the importance of a comprehensive systematic approach to considering differential diagnosis when PMCT shows multiple intracranial hemorrhages suggestive of AHT in an infant.
Breaking the trade-off between thermoelectric (TE) parameters has long been demanded in order to highly enhance its performance. Here, we report the 'trade-off-free' interdependence between thermal ...conductivity (κ) and resistivity (ρ) in a TE/metal tilted multilayer and significant enhancement of TE power generation based on the off-diagonal thermoelectric (ODTE) effect, which generates transverse electrical current in response to vertical thermal current. ρ and κ can be simultaneously decreased by setting charge flow along more-electrically conductive layer and thermal flow across less-thermally conductive perpendicular direction by decreasing the tilting angle. Moreover, introducing porosity in the metal layer enables to decrease in κ without changing ρ, because the macroscopic ρ and κ of the tilted multilayer is respectively governed by the properties of the TE material and the metal with large dissimilarity. The obtained results reveal new strategies for developing trade-off-free TE materials, which will stimulate practical use of TE conversion for waste-heat recovery.
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