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Designing Self-Assembling Chimeric Peptide Nanoparticles with High Stability for Combating Piglet Bacterial Infections

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ADVANCED SCIENCE 2022年第14期9卷 e2105955-e2105955页

作者： Tan, Peng Tang, Qi Xu, Shenrui Zhang, Yucheng Fu, Huiyang Ma, Xi China Agr Univ State Key Lab Anim Nutr Coll Anim Sci & Technol Beijing 100193 Peoples R China

As a novel type of antibiotic alternative, peptide-based antibacterial drug shows potential application prospects attributable to their unique mechanism for lysing the membrane of pathogenic bacteria. However, peptide-based antibacterial drugs suffer from a series of problems, most notably their immature stability, which seriously hinders their application. In this study, self-assembling chimeric peptide nanoparticles (which offer excellent stability in the presence of proteases and salts) are constructed and applied to the treatment of bacterial infections. In vitro studies are used to demonstrate that peptide nanoparticles NPs1 and NPs2 offer broad-spectrum antibacterial activity and desirable biocompatibility, and they retain their antibacterial ability in physiological salt environments. Peptide nanoparticles NPs1 and NPs2 can resist degradation under high concentrations of proteases. In vivo studies illustrate that the toxicity caused by peptide nanoparticles NPs1 and NPs2 is negligible, and these nanoparticles can alleviate systemic bacterial infections in mice and piglets. The membrane permeation mechanism and interference with the cell cycle differ from that of antibiotics and mean that the nanoparticles are at a lower risk of inducing drug resistance. Collectively, these advances may accelerate the development of peptide-based antibacterial nanomaterials and can be applied to the construction of supramolecular nanomaterials.

关键词： nanoparticles peptide-based antibacterial drug self-assembling structure-function relationships

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Gradients of Orientation, Composition, and Hydration of Proteins for Efficient Light Collection by the Cornea of the Horseshoe Crab

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ADVANCED SCIENCE 2022年第33期9卷 e2203371页

作者： Spaeker, Oliver Taylor, Gavin J. Wilts, Bodo D. Slaby, Tomas Abdel-Rahman, Mohamed Ashraf Khalil Scoppola, Ernesto Schmitt, Clemens N. Z. Sztucki, Michael Liu, Jiliang Bertinetti, Luca Wagermaier, Wolfgang Scholtz, Gerhard Fratzl, Peter Politi, Yael Max Planck Inst Colloids & Interfaces Dept Biomat D-14476 Potsdam Germany Inst Globally Distributed Open Res & Educ IGDORE BR-14091310 Ribeirao Preto Brazil Univ Salzburg Chem & Phys Mat Jakob Haringer Str 2a A-5020 Salzburg Austria Univ Fribourg Adolphe Merkle Inst Chemin Verdiers 4 CH-1700 Fribourg Switzerland TELIGHT Libusina Trida 21 Brno 62300 Czech Republic European Synchrotron Radiat Facil ESRF 71 Ave MartyrsCS 40220 F-38043 Grenoble 9 France Tech Univ Dresden B CUBE Ctr Mol Bioengn D-01307 Dresden Germany Humboldt Univ Inst Biol Philippstr 13 D-10115 Berlin Germany

The lateral eyes of the horseshoe crab, Limulus polyphemus, are the largest compound eyes within recent Arthropoda. The cornea of these eyes contains hundreds of inward projecting elongated cuticular cones and concentrate light onto proximal photoreceptor cells. Although this visual system has been extensively studied before, the precise mechanism allowing vision has remained controversial. Correlating high-resolution quantitative refractive index (RI) mapping and structural analysis, it is demonstrated how gradients of RI in the cornea stem from structural and compositional gradients in the cornea. In particular, these RI variations result from the chitin-protein fibers architecture, heterogeneity in protein composition, and bromine doping, as well as spatial variation in water content resulting from matrix cross-linking on the one hand and cuticle porosity on the other hand. Combining the realistic cornea structure and measured RI gradients with full-wave optical modeling and ray tracing, it is revealed that the light collection mechanism switches from refraction-based graded index (GRIN) optics at normal light incidence to combined GRIN and total internal reflection mechanism at high incident angles. The optical properties of the cornea are governed by different mechanisms at different hierarchical levels, demonstrating the remarkable versatility of arthropod cuticle.

关键词： biomaterials chitin-based materials optical materials optical modeling protein composition structure-function relationships vision

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Effect of pH on the structure and stability of irisin, a multifunctional protein: Multispectroscopic and molecular dynamics simulation approach

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JOURNAL OF MOLECULAR structure 2022年 1252卷 132141-132141页

作者： Waseem, Rashid Shamsi, Anas Shahbaz, Mohd Khan, Tanzeel Kazim, Syed Naqui Ahmad, Faizan Hassan, Md Imtaiyaz Islam, Asimul Jamia Millia Islamia Ctr Interdisciplinary Res Basic Sci New Delhi 110025 India Univ Western Cape South African Natl Bioinformat Inst South African Med Res Council Bioinformat Unit Private Bag X17 ZA-7535 Cape Town South Africa South Ural State Univ Lab Computat Modeling Drugs 76 Lenin Prospekt Chelyabinsk 454080 Russia

Irisin is a potential therapeutic agent to prevent or treat various metabolic-related disorders and neurodegenerative diseases viz. Alzheimer's disease (AD). In this study, we have employed a multispectroscopic approach to elucidate the structural and conformational changes in the irisin at varying pH (pH 2.0 to 12.0). The spectroscopic measurements revealed that irisin maintains its structure (both secondary and tertiary) in the alkaline pH range, with minimal structural changes observed across it. However, secondary and tertiary structural alterations were evident across the acidic pH range. CD spectroscopy suggested a gain of the secondary structure in the acidic pH range, implying that irisin is more stable at acidic pH, with maximum stability and compactness observed at pH 4.0. In vitro observations were further validated by in silico studies. Molecular dynamics simulation also suggested that irisin assumes higher stability in the conformational space at pH 4.0 and 6.0 than the rest of the system. This study can serve as a platform to delineate the enhanced functionality of irisin at lower pH that can be implicated in developing therapies for metabolic disorders, including diabetes and obesity. (C) 2021 Elsevier B.V. All rights reserved.

关键词： Irisin structure-function relationships Molecular dynamic simulation

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Structural characteristics of Saccharomyces cerevisiae mannoproteins: Impact of their polysaccharide part

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CARBOHYDRATE POLYMERS 2022年 277卷 118758-118758页

作者： Bicca, Saul Assuncao Poncet-Legrand, Celine Williams, Pascale Nguela, Julie Mekoue Doco, Thierry Vernhet, Aude Univ Montpellier Inst Agro Unite Mixte Rech Sci Enol INRAE Montpellier France Lallemand SAS 19 Rue BriquetiersBP 59 F-31702 Blagnac France

While they have many properties of interest in enology, the structure-function relationships of mannoproteins and the part played by their polysaccharide moiety are not yet well understood. Mannoproteins (MP) extracted with beta-glucanase from a laboratory yeast strain (WT), two of its mutants (Mnn2 with unbranched N-glycosylated chains and Mnn4 without mannosyl-phosphorylation), and an enological strain (Com) were purified and thoroughly characterized. The protein moiety of the four MPs had the same amino acid composition. Glycosyl-linkage and net charge analyses confirmed the expected differences in mutant strain MPs. MP-Com had the highest mannose/glucose ratio followed by MP-WT/MP-Mnn4, and MP-Mnn2 (13.5 > 5.6 approximate to 5.2 > 2.2). The molar mass dependencies of R-g, R-h, and [eta], determined through HPSEC-MALLS-QELS-Viscosimetry, revealed specific conformational properties of mannoproteins related to their nature of highly branched copolymers with two branching levels. It also clearly showed structural differences between MP-Com, MP-WT/Mnn4, and MP Mnn2, and differences between two populations within the four mannoproteins.

关键词： Mannoproteins HPSEC-MALLS-QELS-Viscosimetry Structural analysis Wine Hyperbranched biopolymers structure-function relationships

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Stimuli-Responsive Natural Proteins and Their Applications

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CHEMBIOCHEM 2022年第6期23卷 e202100416-e202100416页

作者： Du, Na Ye, Fangfu Sun, Jing Liu, Kai Univ Chinese Acad Sci Wenzhou Inst Wenzhou 325001 Peoples R China Chinese Acad Sci Changchun Inst Appl Chem State Key Lab Rare Earth Resource Utilizat Changchun 130022 Peoples R China Univ Ulm Inst Organ Chem Albert Einstein Allee 11 D-89081 Ulm Germany Tsinghua Univ Dept Chem Beijing 100084 Peoples R China

Natural proteins are essential biomacromolecules that fulfill versatile functions in the living organism, such as their usage as cytoskeleton, nutriment transporter, homeostasis controller, catalyzer, or immune guarder. Due to the excellent mechanical properties and good biocompatibility/biodegradability, natural protein-based biomaterials are well equipped for prospective applications in various fields. Among these natural proteins, stimuli-responsive proteins can be reversibly and precisely manipulated on demand, rendering the protein-based biomaterials promising candidates for numerous applications, including disease detection, drug delivery, bio-sensing, and regenerative medicine. Therefore, we present some typical natural proteins with diverse physical stimuli-responsive properties, including temperature, light, force, electrical, and magnetic sensing in this review. The structure-function mechanism of these proteins is discussed in detail. Finally, we give a summary and perspective for the development of stimuli-responsive proteins.

关键词： biomaterials medical applications natural proteins stimuli-responses structure-function relationships

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Enhancement of Output Performance of Triboelectric Nanogenerator by Switchable Stimuli in Metal-Organic Frameworks for Photocatalysis

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ACS APPLIED MATERIALS & INTERFACES 2022年第14期14卷 16424-16434页

作者： Huang, Chao Lu, Guizhen Qin, Na Shao, Zhichao Zhang, Dianbo Soutis, Constantinos Zhang, Ying-Ying Mi, Liwei Hou, Hongwei Zhongyuan Univ Technol Ctr Adv Mat Res Zhengzhou 450007 Peoples R China Zhongyuan Univ Technol Henan Key Lab Funct Salt Mat Zhengzhou 450007 Peoples R China Univ Manchester North West Composites Ctr Sch Mat Manchester M13 9PL Lancs England Zhengzhou Univ Coll Chem & Green Catalysis Ctr Zhengzhou 450001 Peoples R China

Precise control of the structure of crystalline materials is an efficient strategy to manipulate the fundamental performance of solids. In metal-organic framework (MOF) materials, this control can be realized by reversible cation-exchange through chemically driven changes in the crystalline state. Herein, we reported that the reversible structural transformations between an anionic Zn-MOF (1) and a topologically equivalent bimetallic Zn/Co-MOF (2) were accomplished. Both MOFs powders and their hybrid composites were used as positive electrode materials to assemble triboelectric nanogenerators (TENGs). The results demonstrated that the output performance of the Zn/Co-MOF-TENG was effectively improved because the introduction of Co ions makes electron transfer easier. Moreover, the output performance of the TENGs based on MOF@PVDF (PVDF = polyvinylidene fluoride) composite films showed that the Zn/Co-MOF@PVDF-TENG possessed much higher output than these corresponding film-based and MOF-based TENGs. As a practical application, the superior output of Zn/CoMOF@PVDF-TENG was used to light an ultraviolet lamp plate for the [2 + 2] photochemical cycloaddition of organometallic macrocycles.

关键词： metal-organic frameworks reversible SC-SC transformations [2+2] photochemical cycloaddition structure-function relationships triboelectric nanogenerators

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Exploring functional Materials by Understanding Beam-Sample Interactions

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ADVANCED functionAL MATERIALS 2022年第27期32卷 2201112-2201112页

作者： Kisielowski, Christian Specht, Petra Rozeveld, Steve Freitag, Bert Kieft, Erik R. Kang, Joo Fielitz, Alyssa J. Fielitz, Thomas R. Dyck, Dirk Yancey, David F. Lawrence Berkeley Natl Lab Mol Foundry One Cyclotron Rd Berkeley CA 94720 USA Univ Calif Berkeley Dept MSE Berkeley CA 94720 USA Dow Chem Co USA Midland MI 48667 USA Thermo Fisher Sci Achtseweg Noord 5 NL-5651 GG Eindhoven Netherlands Univ Antwerp EMAT B-2020 Antwerp Belgium

Ultra-low-dose electron diffraction is performed with a double metal cyanide catalyst (DMC) to understand how electron irradiation stimulates structural alterations in functional materials. The commonly fading diffraction patterns with dose accumulation depend on the irradiated area and the beam current even when below 50 femto Amperes. Heat generation is observed and modeled by statistical, inelastic scattering events to describe how phonon excitations modulate radiation hardness. Specifically, the characteristic 1/e-decay of Bragg intensities from DMC is delayed from 6 to 30 e angstrom(-2) at room temperature, which is comparable to the effect of embedding radiation soft matter in ice. DMC's radiation hardness is enhanced by a latency dose that forms during a phase transformation. This unifying model predicts that a critical dose rate exists for any material that varies between 0.1 and 10(4) e angstrom(-2)s(-1) because of a material dependent competition of heat generation and spread. It shows that Brillouin scattering causes time dependent perturbations in electron irradiated solids that trigger time-temperature-transformations on a time scale of nanoseconds to microseconds at room temperature, which is not included in traditional models describing the decay of Bragg intensities by radiolysis.

关键词： catalysis coherent inelastic electron scattering electron microscopy perturbations structure-function relationships temperature

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Microbial community composition, and not pH, influences lake sediment function

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ECOSPHERE 2022年第5期13卷

作者： Bertolet, Brittni L. Louden, Sydney, I Jones, Stuart E. Univ Notre Dame Dept Biol Sci Notre Dame IN 46556 USA

Lake sediment microbial communities vary across ecosystems and are often differentiated across pH. Additionally, these pH-mediated differences in community composition are often correlated with changes in sediment functioning, such as methane and carbon dioxide production. However, few studies have experimentally tested pH effects on community assembly or considered how microbial community composition influences ecosystem function independent of differences in the environment. We used common garden experiments to test hypotheses about how pH influences microbial community assembly and function in lake sediments. Using inoculum from three acidic lakes and three near-neutral lakes, we found that both pH environment and inoculum source significantly influenced sediment microbial community assembly. However, inoculum source had a larger effect size for both the sediment methanogen and nonmethanogen communities, indicating important roles of dispersal and drift. Additionally, inoculum source, but not pH environment, significantly influenced sediment methane and carbon dioxide production. This research is one of the first to experimentally test the influence of pH on sediment microbial community composition, and in doing so, we show the community composition significantly influences sediment function independent of pH. Understanding how lake sediment microbial communities are influenced by environment is the first step toward mechanistically linking changes in community composition to ecosystem function, and we provide critical evidence for how changes in microbial community assembly with environmental change will likely alter carbon cycling in lake sediments.

关键词： lake methanogenesis microbial community assembly structure-function relationships

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Prediction of visual field defects from macular optical coherence tomography in glaucoma using cluster analysis

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OPHTHALMIC AND PHYSIOLOGICAL OPTICS 2022年第5期42卷 948-964页

作者： Tong, Janelle Alonso-Caneiro, David Kalloniatis, Michael Zangerl, Barbara Univ New South Wales UNSW Ctr Eye Hlth Sydney NSW Australia Univ New South Wales UNSW Sch Optometry & Vis Sci Sydney NSW Australia Queensland Univ Technol Ctr Vis & Eye Res Sch Optometry & Vis Sci Contact Lens & Visual Opt Lab Kelvin Grove Qld Australia Royal Prince Alfred Hosp Coronary Care Unit Sydney NSW Australia

Purpose To assess the accuracy of cluster analysis-based models in predicting visual field (VF) defects from macular ganglion cell-inner plexiform layer (GCIPL) measurements in glaucomatous and healthy cohorts. Methods GCIPL measurements were extracted from posterior pole optical coherence tomography (OCT), from locations corresponding to central VF test grids. Models incorporating cluster analysis methods and corrections for age and fovea to optic disc tilt were developed from 493 healthy participants, and 5th and 1st percentile limits of GCIPL thickness were derived. These limits were compared with pointwise 5th and 1st percentile limits by calculating sensitivities and specificities in an additional 40 normal and 37 glaucomatous participants, as well as applying receiver operating characteristic (ROC) curve analyses to assess the accuracy of predicting VF results from co-localised GCIPL measurements. Results Clustered models demonstrated globally low sensitivity, but high specificity in the glaucoma cohort (0.28-0.53 and 0.77-0.91, respectively), and high specificity in the healthy cohort (0.91-0.98). Clustered models showed similar sensitivities and superior specificities compared with pointwise methods (0.41-0.65 and 0.71-0.98, respectively). There were significant differences in accuracy between clusters, with relatively poor accuracy at peripheral macular locations (p < 0.0001 for all comparisons). Conclusions Cluster analysis-based models incorporating age correction and holistic consideration of fovea to optic disc tilt demonstrated superior performance in predicting VF results to pointwise methods in both glaucomatous and healthy eyes. However, relatively low sensitivity and poorer performance at the peripheral macula indicate that OCT in isolation may be insufficient to predict visual function across the macula accurately. With modifications to criteria for abnormality, the concepts suggested by the described normative models may guide prioritisation of V

关键词： glaucoma optical coherence tomography structure-function relationships visual fields

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Constant pH molecular dynamics simulations: Current status and recent applications

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CURRENT OPINION IN STRUCTURAL BIOLOGY 2022年 77卷 102498页

作者： de Oliveira, Vinicius Martins Liu, Ruibin Shen, Jana Univ Maryland Dept Pharmaceut Sci Sch Pharm 20 Penn St Baltimore MD 20201 USA

Many important protein functions are carried out through proton-coupled conformational dynamics. Thus, the ability to accurately model protonation states dynamically has wide-ranging implications. Over the past two decades, two main types of constant pH methods (discrete and continuous) have been developed to enable proton-coupled molecular dynamics (MD) simulations. In this short review, we discuss the current status of the development and highlight recent applications that have advanced our understanding of protein structure-function relationships. We conclude the review by outlining the remaining challenges in the method development and projecting important areas for future applications.

关键词： Protein electrostatics Proton transfer structure-function relationships

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