Small tripeptides composed entirely of β-amino acids have been shown to self-assemble into fibres following acylation of the N-terminus. Given the use of Fmoc as a strategy to initiate self-assembly in α-peptides, we hypothesized that the acyl cap can be replaced by an Fmoc without perturbation to the self-assembly and enable simpler synthetic protocols. We therefore replaced the -acyl cap for an Fmoc group and herein we show that these Fmoc-protected β-peptides produce regular spherical particles, rather than fibrous structures, that are stable and capable of encapsulating cargo.
View Article and Find Full Text PDFRibosome-associated quality control (RQC) pathway is responsible for degradation of nascent polypeptides in aberrantly stalled ribosomes, and its defects may lead to neurological diseases. However, the underlying molecular mechanism of how RQC dysfunction elicits neurological disorders remains poorly understood. Here we revealed that neurons with knockout (KO) of ubiquitin ligase LTN1, a key gene in the RQC pathway, show developmental defects in neurons via upregulation of TTC3 and UFMylation signaling proteins.
View Article and Find Full Text PDFAcademic challenges and failure are inevitable in pursuit of higher education. According to the self-worth theory, trying hard but failing implies low ability that would be a threat to personal worth, thus preventing students from approaching academic challenges. Nevertheless, previous studies have shown that students in the Confucian-heritage contexts (CHCs) tend to persist rather than quit in the face of academic failure.
View Article and Find Full Text PDFWhat Works Clearinghouse (WWC, 2022) recommends a design-comparable effect size (D-CES; i.e., g) to gauge an intervention in single-case experimental design (SCED) studies, or to synthesize findings in meta-analysis.
View Article and Find Full Text PDFPrevious research indicated that instructors holding entity belief tended to judge students to have low ability and provided ability-comforting feedback following math failure. Students receiving such feedback tended to quit and change course, creating a potential decrease in the pool of students pursuing math related fields. In Confucian heritage cultures (CHCs), the ideal society is primarily based on fulfillment of duties.
View Article and Find Full Text PDFIntegrated science, technology, engineering, and mathematics (STEM) embedding project-based learning (i-STEM PjBL) is still faced with challenges, and its educational values have not been revealed, which is what the study aimed to explore. Participants consisted of 48 freshmen from a senior high school, including 27 male students and 21 female students. The open-ended questionnaire and the interview for the students were administrated after the i-STEM PjBL.
View Article and Find Full Text PDFMask-wearing is the simplest yet most effective preventive behavior during COVID-19. However, it has sparked great controversy, particularly in America. Little is known about what psychosocial factors predict people's decision to mask.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
February 2022
The ability to selectively react one functional group in the presence of another underpins efficient reaction sequences. Despite many designer catalytic systems being reported for hydroboration reactions, which allow introduction of a functional handle for cross-coupling or act as mild method for reducing polar functionality, these platforms rarely deal with more complex systems where multiple potentially reactive sites exist. Here we demonstrate, for the first time, the ability to use light to distinguish between ketones and carboxylic acids in more complex molecules.
View Article and Find Full Text PDFprotein synthesis by the ribosome and its multitude of co-factors must occur in a tightly regulated manner to ensure that the correct proteins are produced accurately at the right time and, in some cases, also in the proper location. With novel techniques such as ribosome profiling and cryogenic electron microscopy, our understanding of this basic biological process is better than ever and continues to grow. Concurrently, increasing attention is focused on how translational regulation in the brain may be disrupted during the progression of various neurological disorders.
View Article and Find Full Text PDFWound dressing, which prevents dehydration and provides a physical barrier against infection to wound beds, can improve wound healing. The interactions between extracellular matrix (ECM) and growth factors is critical to the healing process. Electrospun nanofibers are promising templates for wound dressings due to the structure similarity to ECM of skin.
View Article and Find Full Text PDFPolymers (Basel)
September 2018
In this study, we combined two kinds of natural polymers, chitosan and keratin, to develop a portable composite membrane via UV irradiation. UV-crosslinking without an additional chemical agent makes the fabrication more ideal by reducing reactants and avoiding residual toxic chemicals. This novel composite could perform synergistic functions benefitting from chitosan and keratin; including a strong mechanical strength, biodegradability, biocompatibility, better cell adhesion, and proliferation characteristics.
View Article and Find Full Text PDFKeratin, a natural biomaterial derived from wool or human hair, has the intrinsic ability to interact with different types of cells and the potential to serve as a controllable extracellular matrix that can be used a scaffold for tissue engineering. In this study, we demonstrated a simple and fast technique to construct 3D keratin scaffolds for accelerated wound healing using a lyophilization method based on extraction of keratin from human hair. The physical properties of the keratin scaffolds such as water uptake, pore size, and porosity can be adjusted by changing the protein concentrations during the fabrication process.
View Article and Find Full Text PDFAn advanced material interface is modified by using a substrate-independent coating of detachable poly-para-xylylene, enabling dynamical control of the immobilization and detachment of biomolecules, and a previously installed biological function is deactivated or tuned with reduced activity. The induction of osteogenesis activity, and subsequent deactivation of such osteogenesis activity, is demonstrated.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2016
An integrated cell for the solar-driven splitting of water consists of multiple functional components and couples various photoelectrochemical (PEC) processes at different length and time scales. The overall solar-to-hydrogen (STH) conversion efficiency of such a system depends on the performance and materials properties of the individual components as well as on the component integration, overall device architecture, and system operating conditions. This Review focuses on the modeling- and simulation-guided development and implementation of solar-driven water-splitting prototypes from a holistic viewpoint that explores the various interplays between the components.
View Article and Find Full Text PDFNeurons are characterized by subcellular compartments, such as axons, dendrites and synapses, that have highly specialized morphologies and biochemical specificities. Cortactin-binding protein 2 (CTTNBP2), a neuron-specific F-actin regulator, has been shown to play a role in the regulation of dendritic spine formation and their maintenance. Here, we show that, in addition to F-actin, CTTNBP2 also associates with microtubules before mature dendritic spines form.
View Article and Find Full Text PDFCortactin-binding protein 2 (CTTNBP2) interacts with cortactin to regulate cortactin mobility and control dendritic spine formation. CTTNBP2 has also been associated with autistic spectrum disorder. The regulation of dendritic spinogenesis could explain the association of CTTNBP2 with autism.
View Article and Find Full Text PDFDendritic spines, the actin-rich protrusions emerging from dendrites, are the locations of excitatory synapses in mammalian brains. Many molecules that regulate actin dynamics also influence the morphology and/or density of dendritic spines. Since dendritic spines are neuron-specific subcellular structures, neuron-specific proteins or signals are expected to control spinogenesis.
View Article and Find Full Text PDFObjective: Rapid Genetic Screening of Leber's hereditary optic neuropathy (LHON) with mtDNA G11778A mutation by allele-specific polymerase chain reaction (AS-PCR) with whole blood.
Methods: Whole blood with anticoagulant was used as a template of AS-PCR for the analysis of LHON with mtDNA G11778A point mutation. The amplified DNA fragment was directly observed by electrophoretogram with ethidium bromide stained.
The purpose of the study is to investigate the frequency of common pathogenic primary mitochondrial DNA mutations in pedigrees of Leber's hereditary optic neuropathy (LHON). Mutations were determined by polymerase chain reaction (PCR), single-stranded conformational polymorphism (SSCP) and DNA sequencing. Twenty-two patients with suspicion of LHON and twenty-one their maternal relatives underwent molecular genetic evaluation.
View Article and Find Full Text PDFBiochem Biophys Res Commun
October 2004
The Archaeal protein RadA, a RecA/Rad51 homolog, is able to promote pairing and exchange of DNA strands with homologous sequences. Here, we have expressed, purified, and crystallized the catalytically active RadA protein from Sulfolobus solfataricus (Sso). Preliminary X-ray analysis indicated that Sso RadA protein likely forms helical filament in protein crystals.
View Article and Find Full Text PDFIncreasing evidence has shown that intrinsic disorder of proteins plays a key role in their biological functions. In the case of undecaprenyl pyrophosphate synthase (UPPs), which catalyzes the chain elongation of farnesyl pyrophosphate (FPP) to undecaprenyl pyrophosphate via eight consecutive condensation reactions with isopentenyl pyrophosphate, a highly flexible loop 72-83 was previously linked to protein conformational change required for catalysis [Chen, Y. H.
View Article and Find Full Text PDFOctaprenyl pyrophosphate synthase (OPPs) catalyzes the sequential condensation of five molecules of isopentenyl pyrophosphate with farnesyl pyrophosphate to generate all-trans C40-octaprenyl pyrophosphate, which constitutes the side chain of ubiquinone. Due to the slow product release, a long-chain polyprenyl pyrophosphate synthase often requires detergent or another factor for optimal activity. Our previous studies in examining the activity enhancement of Escherichia coli undecaprenyl pyrophosphate synthase have demonstrated a switch of the rate-determining step from product release to isopentenyl pyrophosphate (IPP) condensation reaction in the presence of Triton [12].
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