RESUMEN

Excess nitrites are potentially threatening to human health, so it is urgent to develop accurate and sensitive methods. The development of sensors can provide early warning of possible hazards and alert people to protect public health. This work presents an NiSx@MoS2-composite with excellent electrochemical activity, representing a key finding for highly sensitive NO2- detection and sensor development. With the assistance of NiSx@MoS2, this electrochemical sensor has excellent quantitative detection performance. It has a wide detection range (0.0001-0.0020 mg/mL) and a low detection limit (1.863*10-5 mg/mL) for NO2-. This electrochemical sensor maintains excellent specificity among numerous interferences, and it completes the accurate detection of different real food samples. Pleasingly, the electrochemical sensor has satisfactory repeatability stability, and potential for practical applications. It would demonstrate tremendous potential in scientific dietary guidance, food safety detection and other fields.

Asunto(s)

Disulfuros , Técnicas Electroquímicas , Límite de Detección , Molibdeno , Molibdeno/química , Técnicas Electroquímicas/instrumentación , Disulfuros/química , Nitritos/análisis , Contaminación de Alimentos/análisis

RESUMEN

BACKGROUND: Curcumin has been used in traditional medicine because of its pharmacological activity, including antioxidant, antibacterial, anticancer, and anticarcinogenic properties. Therefore, sensitive and selective monitoring of curcumin is highly demand for practical application. RESULTS: In this study, we describe the construction of a fluorescence method for curcumin assay based on nitrogen-doped MoS2 quantum dots (N-MoS2 QDs). The N-MoS2 QDs are constructed by a solvothermal method using sodium molybdate and Cys as precursors. With the addition of curcumin, the bright blue fluorescence of N-MoS2 QDs is quenched by the inner filter effect (IFE). The QDs emitted bright blue fluorescence and could be quenched by the addition of curcumin via IFE. The dynamic range is the range of 0.1-10 µM for curcumin detection, with a detection limit of 59 nM. N-MoS2 QDs were applied for curcumin assay in real samples with good recovery. In addition, the N-MoS2 QDs exhibited relative low cytotoxicity and could be applied for fluorescence-based imaging in biological samples. SIGNIFICANCE: Our study indicates that the sensor possesses good selectivity to monitor curcumin in water samples, human urine samples, ginger powder samples, mustard samples, and curry samples with satisfactory recoveries. The N-MoS2 QDs possess less cytotoxicity with excellent biocompatibility and were applied for in vitro cell imaging.

Asunto(s)

Curcumina , Disulfuros , Colorantes Fluorescentes , Molibdeno , Nitrógeno , Puntos Cuánticos , Curcumina/química , Curcumina/farmacología , Puntos Cuánticos/química , Molibdeno/química , Humanos , Disulfuros/química , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Nitrógeno/química , Imagen Óptica , Límite de Detección , Espectrometría de Fluorescencia , Supervivencia Celular/efectos de los fármacos

RESUMEN

Peptides are valuable for therapeutic development, with multicyclic peptides showing promise in mimicking antigen-binding potency of antibodies. However, our capability to engineer multicyclic peptide scaffolds, particularly for the construction of large combinatorial libraries, is still limited. Here, we study the interplay of disulfide pairing between three biscysteine motifs, and designed a range of triscysteine motifs with unique disulfide-directing capability for regulating the oxidative folding of multicyclic peptides. We demonstrate that incorporating these motifs into random sequences allows the design of disulfide-directed multicyclic peptide (DDMP) libraries with up to four disulfide bonds, which have been applied for the successful discovery of peptide binders with nanomolar affinity to several challenging targets. This study encourages the use of more diverse disulfide-directing motifs for creating multicyclic peptide libraries and opens an avenue for discovering functional peptides in sequence and structural space beyond existing peptide scaffolds, potentially advancing the field of peptide drug discovery.

Asunto(s)

Cisteína , Disulfuros , Biblioteca de Péptidos , Disulfuros/química , Cisteína/química , Secuencias de Aminoácidos , Descubrimiento de Drogas/métodos , Secuencia de Aminoácidos , Péptidos/química , Péptidos/metabolismo , Péptidos Cíclicos/química , Péptidos Cíclicos/metabolismo , Unión Proteica , Humanos , Oxidación-Reducción , Pliegue de Proteína

RESUMEN

In present work, synthesis of a nanohybrid material using Fe and MoS2 has been performed via a cost-effective and environmentally friendly route for sustainable manufacturing innovation. Rice straw extract was prepared and used as a reducing and chelating agent to synthesize the nanohybrid material by mixing it with molybdenum disulfide (MoS2) and ferric nitrate [Fe (NO3)3.9H2O], followed by heating and calcination. The X-ray diffraction (XRD) pattern confirms the formation of a nanohybrid consisting of monoclinic Fe2(MoO4)3, cubic Fe2.957O4, and orthorhombic FeS with 86% consisting of Fe2(MoO4)3. The properties were analyzed through Fourier-transformed infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results of the dynamic light scattering (DLS) study revealed a heterogeneous size distribution, with an average particle size of 48.42 nm for 18% of particles and 384.54 nm for 82% of particles. Additionally, the zeta potential was measured to be -18.88 mV, suggesting moderate stability. X-ray photoelectron spectroscopy (XPS) results confirmed the presence of both Fe2+ and Fe3+ oxidation states along with the presence of Molybdenum (Mo), oxygen (O), and Sulphur (S). The prepared nanohybrid material exhibited a band gap of 2.95 eV, and the photoluminescence intensity increased almost twice that of bare MoS2. The present work holds potential applications in photo luminescent nanoplatform for biomedical applications.

Asunto(s)

Disulfuros , Tecnología Química Verde , Molibdeno , Oryza , Tamaño de la Partícula , Molibdeno/química , Disulfuros/química , Oryza/química , Hierro/química , Propiedades de Superficie

RESUMEN

This study demonstrates the use of computational methods to simulate the molecular dynamics involved in hemoglobin concentration sensing, utilizing Material Studio and the TCAD Silvaco device simulator. A non-invasive and flexible Graphene/MoS2 heterostructure has been proposed for sensing hemoglobin concentration in blood samples. The findings reveal a notable shift in the wavelength-dependent refractive index and extinction coefficient, as well as significant changes in the absorption coefficient and reflectivity of the Graphene/MoS2 heterostructure in response to different hemoglobin concentrations, specifically within an approximate range of 0.3 µm to 1 µm. Moreover, the spectral response of the heterostructure demonstrates that at a particular wavelength of approximately 600 nm, a maximum response is obtained. This wavelength can be considered optimal for detecting various levels of hemoglobin using this heterostructure. The anticipated outcome is a comprehensive understanding of the fundamental principles, ultimately resulting in the development of an exceptionally sensitive platform for detecting hemoglobin concentration.

Asunto(s)

Disulfuros , Grafito , Hemoglobinas , Molibdeno , Grafito/química , Hemoglobinas/análisis , Hemoglobinas/química , Molibdeno/química , Humanos , Disulfuros/química , Disulfuros/sangre , Simulación de Dinámica Molecular , Técnicas Biosensibles/métodos , Técnicas Biosensibles/instrumentación

RESUMEN

The complex structure of monoclonal antibodies (mAbs) expressed in Chinese hamster ovary (CHO) cells may result in the accumulation of unfolded proteins, triggering endoplasmic reticulum (ER) stress and an unfolded protein response (UPR). If the protein folding ability cannot maintain ER homeostasis, the cell will shut down protein translation and ultimately induce apoptosis. We co-overexpressed HsQSOX1b and survivin proteins in the antibody-producing cell line CHO-PAb to obtain a new cell line, CHO-PAb-QS. Compared with CHO-PAb cells, the survival time of CHO-PAb-QS cells in batch culture was extended by 2 days, and the antibody accumulation and productivity were increased by 52% and 45%, respectively. The proportion of (HC-LC)2 was approximately doubled in the CHO-PAb-QS cells, which adapted to the accelerated disulfide bond folding capacity by upregulating the UPR's strength and increasing the ER content. The results of the apoptosis assays indicated that the CHO-PAb-QS cell line exhibited more excellent resistance to apoptosis induced by ER stress. Finally, CHO-PAb-QS cells exhibited mild oxidative stress but did not significantly alter the redox status. This study demonstrated that strategies based on HsQSOX1b and survivin co-overexpression could facilitate protein disulfide bond folding and anti-apoptosis ability, enhancing antibody production efficiency in CHO cell lines.

Asunto(s)

Apoptosis , Cricetulus , Disulfuros , Pliegue de Proteína , Células CHO , Animales , Disulfuros/metabolismo , Disulfuros/química , Estrés del Retículo Endoplásmico , Respuesta de Proteína Desplegada , Formación de Anticuerpos , Anticuerpos Monoclonales , Cricetinae , Survivin/metabolismo , Humanos , Retículo Endoplásmico/metabolismo , Estrés Oxidativo

RESUMEN

Oligonucleotide drugs are shining in clinical therapeutics, but efficient and safe delivery systems severely limit their widespread use. A disulfide unit technology platform based on dynamic thiol exchange chemistry at the cell membrane has the potential for drug delivery. However, the alteration of the disulfide unit CSSC dihedral angle induced by different substituents directly affects the effectiveness of this technology and its stability. Previously, we constructed a trivalent low dihedral angle disulfide unit that can effectively promote the cellular uptake of small molecules. Here, we constructed a novel disulfide unit-masked oligonucleotide hybrid based on a low dihedral angle disulfide unit, motivated by prodrug design. Cellular imaging results showed that such a system exhibited superior cellular delivery efficiency than the commercial Lipo2000 without cytotoxicity. The thiol reagents significantly reduced its cellular uptake (57-74%), which proved to be endocytosis-independent. In addition, in vivo distribution experiments in mice showed that such systems can be rapidly distributed in liver tissues with a duration of action of more than 24 h, representing a potential means of silencing genes involved in the pathogenesis of liver-like diseases. In conclusion, this trivalent disulfide unit-masked system we constructed can effectively deliver large oligonucleotide drugs.

Asunto(s)

Disulfuros , Oligonucleótidos , Disulfuros/química , Animales , Oligonucleótidos/química , Ratones , Humanos , Sistemas de Liberación de Medicamentos , Hígado/metabolismo , Hígado/efectos de los fármacos

RESUMEN

Chronic diabetic wounds present formidable challenges, marked by uncontrolled bacterial infections, prolonged inflammation, and impaired angiogenesis. The evolving landscape of photo-responsive antibacterial therapy holds great promise in addressing these multifaceted issues, with a particular focus on leveraging the distinctive properties of 2D heterojunction materials. In this investigation, we engineered composite sprayed hydrogels, seamlessly integrating Bi/MoS2 nano-heterojunctions. Capitalizing on the synergistic interplay between photocatalytic antibacterial and photothermal antibacterial mechanisms, the Bi/MoS2 heterojunction, guided by its localized surface plasmon resonance, demonstrated outstanding antibacterial efficacy within a mere 10-minute exposure to 808 nm near-infrared light. This accelerated sterilization both in vitro and in vivo, consequently expediting wound healing. The sprayed composite gel not only furnishes protective shielding for skin tissues but also fosters endothelial cell proliferation, vascularization, and angiogenesis. This safe and ultrafast sterilizing hydrogel presents immense potential for application in antimicrobial dressings, thereby offering a promising avenue for diabetic wound healing.

Asunto(s)

Antibacterianos , Molibdeno , Cicatrización de Heridas , Antibacterianos/farmacología , Antibacterianos/química , Cicatrización de Heridas/efectos de los fármacos , Animales , Molibdeno/química , Molibdeno/farmacología , Hidrogeles/química , Hidrogeles/farmacología , Disulfuros/química , Fibrina/química , Ratones , Humanos , Escherichia coli/efectos de los fármacos , Células Endoteliales de la Vena Umbilical Humana , Diabetes Mellitus Experimental , Ratas

RESUMEN

Implantable polymeric biodegradable devices, such as biodegradable vascular scaffolds, cannot be fully visualized using standard X-ray-based techniques, compromising their performance due to malposition after deployment. To address this challenge, we describe a new radiopaque and photocurable liquid polymer-ceramic composite (mPDC-MoS2) consisting of methacrylated poly(1,12 dodecamethylene citrate) (mPDC) and molybdenum disulfide (MoS2) nanosheets. The composite was used as an ink with microcontinuous liquid interface production (µCLIP) to fabricate bioresorbable vascular scaffolds (BVS). Prints exhibited excellent crimping and expansion mechanics without strut failures and, importantly, with X-ray visibility in air and muscle tissue. Notably, MoS2 nanosheets displayed physical degradation over time in phosphate-buffered saline solution, suggesting the potential for producing radiopaque, fully bioresorbable devices. mPDC-MoS2 is a promising bioresorbable X-ray-visible composite material suitable for 3D printing medical devices, such as vascular scaffolds, that require noninvasive X-ray-based monitoring techniques for implantation and evaluation. This innovative biomaterial composite system holds significant promise for the development of biocompatible, fluoroscopically visible medical implants, potentially enhancing patient outcomes and reducing medical complications.

Asunto(s)

Disulfuros , Molibdeno , Impresión Tridimensional , Andamios del Tejido , Molibdeno/química , Disulfuros/química , Andamios del Tejido/química , Implantes Absorbibles , Polímeros/química , Materiales Biocompatibles/química , Citratos/química , Animales

RESUMEN

2H-phase molybdenum disulfide (2H-MoS2) has been considered to be a chemically stable two-dimensional (2D) nanomaterial. Nonetheless, the persistence of 2H-MoS2 in the presence of environmental redox-active matrices, such as naturally occurring oxidants (e.g., manganese dioxide (MnO2)) and natural organic matter (NOM), remains largely unknown. Herein, we examined the interplay between 2H-MoS2, MnO2 (a common natural oxidant), and NOM species (i.e., Aldrich humic acid (ALHA) and Suwannee River natural organic matter (SRNOM)). The results show that MnO2 accelerates the oxidative dissolution of 2H-MoS2, regardless of the presence of dissolved oxygen. The effect of NOM on the MnO2-induced fate of 2H-MoS2 was found to depend on its affinity for 2H-MoS2 and the functionality of NOM. ALHA preferentially adsorbed on hydrophobic 2H-MoS2 nanosheets due to the enrichment of reductive polycyclic aromatics and polyphenolic constituents. The preferential ALHA adsorption counteracted the MnO2-triggered oxidative transformation of 2H-MoS2, as revealed by the cathodic response of 2H-MoS2 (i.e., decreased the open circuit potential by 0.0338 V) and the emergence of reductive Mo‒C bonds at 228.8 and 231.9 eV upon the addition of ALHA. This work evaluated the persistence of 2H-MoS2, illustrating its susceptibility to decomposition by naturally occurring oxidants and the influence of NOM on it. These findings are crucial for revealing the fate and transport of MoS2 in aquatic environments and provide guidelines for related applications in natural or engineered systems for MoS2 and potentially other 2D materials.

Asunto(s)

Disulfuros , Sustancias Húmicas , Molibdeno , Oxidantes , Molibdeno/química , Disulfuros/química , Oxidantes/química , Óxidos/química , Nanoestructuras/química , Oxidación-Reducción , Compuestos de Manganeso/química , Adsorción

RESUMEN

The reactions of radicals with human serum albumin (HSA) under reductive stress conditions were studied using pulse radiolysis and photochemical methods. It was proved that irradiation of HSA solutions under reductive stress conditions results in the formation of stable protein aggregates. HSA aggregates induced by ionizing radiation are characterized by unique emission, different from the UV emission of non-irradiated solutions. The comparison of transient absorption spectra and the reactivity of hydrated electrons (eaq-) with amino acids or HSA suggests that electron attachment to disulfide bonds is responsible for the transient spectrum recorded in the case of albumin solutions. The reactions of eaq- and CO2•- with HSA lead to the formation of the same products. Recombination of sulfur-centered radicals plays a crucial role in the generation of HSA nanoparticles, which are stabilized by intermolecular disulfide bonds. The process of creating disulfide bridges under the influence of ionizing radiation is a promising method for the synthesis of biocompatible protein nanostructures for medical applications. Our Raman spectroscopy studies indicate strong modification of disulfide bonds and confirm the aggregation of albumins as well. Low-temperature measurements indicate the possibility of electron tunneling through the HSA protein structure to specific CyS-SCy bridges. The current study showed that the efficiency of HSA aggregation depends on two main factors: dose rate (number of pulses per unit time in the case of pulse radiolysis) and the temperature of the irradiated solution.

Asunto(s)

Agregado de Proteínas , Albúmina Sérica Humana , Humanos , Albúmina Sérica Humana/química , Albúmina Sérica Humana/metabolismo , Disulfuros/química , Oxidación-Reducción , Espectrometría Raman , Radicales Libres/química , Radiólisis de Impulso

RESUMEN

Numerous enveloped viruses, such as coronaviruses, influenza, and respiratory syncytial virus (RSV), utilize class I fusion proteins for cell entry. During this process, the proteins transition from a prefusion to a postfusion state, undergoing substantial and irreversible conformational changes. The prefusion conformation has repeatedly shown significant potential in vaccine development. However, the instability of this state poses challenges for its practical application in vaccines. While non-native disulfides have been effective in maintaining the prefusion structure, identifying stabilizing disulfide bonds remains an intricate task. Here, we present a general computational approach to systematically identify prefusion-stabilizing disulfides. Our method assesses the geometric constraints of disulfide bonds and introduces a ranking system to estimate their potential in stabilizing the prefusion conformation. We hypothesized that disulfides restricting the initial stages of the conformational switch could offer higher stability to the prefusion state than those preventing unfolding at a later stage. The implementation of our algorithm on the RSV F protein led to the discovery of prefusion-stabilizing disulfides that supported our hypothesis. Furthermore, the evaluation of our top design as a vaccine candidate in a cotton rat model demonstrated robust protection against RSV infection, highlighting the potential of our approach for vaccine development.

Asunto(s)

Disulfuros , Proteínas Virales de Fusión , Disulfuros/química , Animales , Proteínas Virales de Fusión/inmunología , Proteínas Virales de Fusión/química , Humanos , Infecciones por Virus Sincitial Respiratorio/inmunología , Infecciones por Virus Sincitial Respiratorio/prevención & control , Infecciones por Virus Sincitial Respiratorio/virología , Estabilidad Proteica , Diseño Asistido por Computadora , Conformación Proteica , Virus Sincitiales Respiratorios/inmunología , Vacunas contra Virus Sincitial Respiratorio/inmunología , Ratas , Modelos Moleculares

RESUMEN

In this study, we developed a wearable nanozyme-enzyme electrochemical biosensor that enablies sweat lactate monitoring. The biosensor comprises a flexible electrode system prepared on a polyimide (PI) film and the Janus textile for unidirectional sweat transport. We obtained favorable electrochemical activities for hydrogen peroxide reduction by modifying the laser-scribed graphene (LSG) electrode with cerium dioxide (CeO2)-molybdenum disulphide (MoS2) nanozyme and gold nanoparticles (AuNPs). By further immobilisation of lactate oxidase (LOx), the proposed biosensor achieves chronoamperometric lactate detection in artificial sweat within a range of 0.1-50.0 mM, a high sensitivity of 25.58 µA mM-1cm-2 and a limit of detection (LoD) down to 0.135 mM, which fully meets the requirements of clinical diagnostics. We demonstrated accurate lactate measurements in spiked artificial sweat, which is consistent with standard ELISA results. To monitor the sweat produced by volunteers while exercising, we conducted on-body tests, showcasing the wearable biosensor's ability to provide clinical sweat lactate diagnosis for medical treatment and sports management.

Asunto(s)

Técnicas Biosensibles , Técnicas Electroquímicas , Oro , Grafito , Ácido Láctico , Oxigenasas de Función Mixta , Sudor , Dispositivos Electrónicos Vestibles , Técnicas Biosensibles/instrumentación , Sudor/química , Humanos , Ácido Láctico/análisis , Técnicas Electroquímicas/instrumentación , Oxigenasas de Función Mixta/química , Oxigenasas de Función Mixta/metabolismo , Oro/química , Grafito/química , Enzimas Inmovilizadas/química , Molibdeno/química , Nanopartículas del Metal/química , Electrodos , Disulfuros/química , Límite de Detección

RESUMEN

Garlic is a vegetable with numerous pro-health properties, showing high antioxidant capacity, and cytotoxicity for various malignant cells. The inhibition of cell proliferation by garlic is mainly attributed to the organosulfur compounds (OSCs), but it is far from obvious which constituents of garlic indeed participate in the antioxidant and cytotoxic action of garlic extracts. This study aimed to obtain insight into this question by examining the antioxidant activity and cytotoxicity of six OSCs and five phenolics present in garlic. Three common assays of antioxidant activity were employed (ABTS● decolorization, DPPH● decolorization, and FRAP). Cytotoxicity of both classes of compounds to PEO1 and SKOV-3 ovarian cancer cells, and MRC-5 fibroblasts was compared. Negligible antioxidant activities of the studied OSCs (alliin, allicin, S-allyl-D-cysteine, allyl sulfide, diallyl disulfide, and diallyl trisulfide) were observed, excluding the possibility of any significant contribution of these compounds to the total antioxidant capacity (TAC) of garlic extracts estimated by the commonly used reductive assays. Comparable cytotoxic activities of OSCs and phenolics (caffeic, p-coumaric, ferulic, gallic acids, and quercetin) indicate that both classes of compounds may contribute to the cytotoxic action of garlic.

Asunto(s)

Compuestos Alílicos , Antioxidantes , Disulfuros , Ajo , Fenoles , Extractos Vegetales , Sulfuros , Ácidos Sulfínicos , Ajo/química , Humanos , Antioxidantes/farmacología , Antioxidantes/química , Fenoles/farmacología , Fenoles/química , Disulfuros/farmacología , Disulfuros/química , Línea Celular Tumoral , Extractos Vegetales/farmacología , Extractos Vegetales/química , Ácidos Sulfínicos/farmacología , Ácidos Sulfínicos/química , Sulfuros/farmacología , Sulfuros/química , Compuestos Alílicos/farmacología , Compuestos Alílicos/química , Compuestos de Azufre/farmacología , Compuestos de Azufre/química , Cisteína/análogos & derivados , Cisteína/química , Cisteína/farmacología , Supervivencia Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo

RESUMEN

BACKGROUND: The importance of multi-target simultaneous detection lies in its ability to significantly boost detection efficiency, making it invaluable for rapid and cost-effective testing. Photoelectrochemical (PEC) sensors have emerged as promising candidates for detecting harmful substances and biomarkers, attributable to their unparalleled sensitivity, minimal background signal, cost-effectiveness, equipment simplicity, and outstanding repeatability. However, designing an effective multi-target detection strategy remains a challenging task in the PEC sensing field. Consequently, there is a pressing need to address the development of PEC sensors capable of simultaneously detecting multiple targets. RESULTS: CdIn2S4/V-MoS2 heterojunctions were successfully prepared via a hydrothermal method. These heterojunctions exhibited a high photocurrent intensity, representing a 1.53-fold enhancement compared to CdIn2S4 alone. Next, we designed a multi-channel aptasensing chip using ITO as the substrate. Three working electrodes were created via laser etching and subsequently modified with CdIn2S4/V-MoS2 heterojunctions. Thiolated aptamers were then self-assembled onto the CdIn2S4/V-MoS2 heterojunctions via covalent bonds, serving as recognition tool. By empolying the CdIn2S4/V-MoS2 heterojunctions as the sensing platform and aptamers as recognition tool, we successfully developed a disposable aptasensing chip for the simultaneous PEC detection of three typical mycotoxins (aflatoxin B1 (AFB1), ochratoxin A (OTA), and zearalenone (ZEN)). This aptasensing chip exhibited wide detection range for AFB1 (0.05-50 ng/mL), OTA (0.05-500 ng/mL), and ZEN (0.1-250 ng/mL). Furthermore, it demonstrated ultra-low detection limits of 0.017 ng/mL for AFB1, 0.016 ng/mL for OTA, and 0.033 ng/mL for ZEN. SIGNIFICANCE AND NOVELTY: The aptasensing chip stands out for its cost-effectiveness, simplicity of fabrication, and multi-channel capabilities. The versatility and practicality enable it to serve as a powerful platform for designing multi-channel PEC aptasensors. With its ability to detect multiple targets with high sensitivity and specificity, the aptasensing chip holds immense potential for applications across diverse fields, such as environmental monitoring, clinical diagnostics, and food safety monitoring, where multi-target detection is crucial.

Asunto(s)

Aptámeros de Nucleótidos , Disulfuros , Técnicas Electroquímicas , Molibdeno , Semiconductores , Molibdeno/química , Técnicas Electroquímicas/instrumentación , Técnicas Electroquímicas/métodos , Aptámeros de Nucleótidos/química , Disulfuros/química , Límite de Detección , Nanoestructuras/química , Procesos Fotoquímicos , Micotoxinas/análisis , Técnicas Biosensibles , Compuestos de Cadmio/química , Ocratoxinas/análisis

RESUMEN

The weak contacts between disulfide linkages and carbonyl groups are anticipated to be important in determining the structure and function of enzymes and proteins. However, the characteristics of the disulfide-carbonyl n → π* (nSS → π* C═O) interactions remain unexplored. Herein, we investigated the nSS → π* C═O interactions in the gas phase and in proteins. Rotational spectroscopic investigation of a model complex of allyl methyl disulfide with formaldehyde identified two structures, both of which are stabilized through a dominant nSS → π* C═O interaction. Surveys of the Protein Data Bank revealed the occurrence of 18 675 nSS → π* C═O interactions associated with 15 320 disulfide bonds in 7105 protein structures. Further theoretical analyses characterize the bonding nature of the nSS → π* C═O interactions. This study provides an in-depth understanding of the stabilizing effect of the nSS → π* C═O interactions in small molecular complexes and biomacromolecules.

Asunto(s)

Disulfuros , Gases , Proteínas , Disulfuros/química , Gases/química , Proteínas/química , Formaldehído/química , Modelos Moleculares

RESUMEN

Influenza virus infection poses a continual menace to public health. Here, we developed soluble trimeric HA ectodomain vaccines by establishing interprotomer disulfide bonds in the stem region, which effectively preserve the native antigenicity of stem epitopes. The stable trimeric H1 ectodomain proteins exhibited higher thermal stabilities in comparison with unmodified HAs and showed strong binding activities towards a panel of anti-stem cross-reactive antibodies that recognize either interprotomer or intraprotomer epitopes. Negative stain transmission electron microscopy (TEM) analysis revealed the stable trimer architecture of the interprotomer disulfide-stapled WA11#5, NC99#2, and FLD#1 proteins as well as the irregular aggregation of unmodified HA molecules. Immunizations of mice with those trimeric HA ectodomain vaccines formulated with incomplete Freund's adjuvant elicited significantly more potent cross-neutralizing antibody responses and offered broader immuno-protection against lethal infections with heterologous influenza strains compared to unmodified HA proteins. Additionally, the findings of our study indicate that elevated levels of HA stem-specific antibody responses correlate with strengthened cross-protections. Our design strategy has proven effective in trimerizing HA ectodomains derived from both influenza A and B viruses, thereby providing a valuable reference for designing future influenza HA immunogens.

Asunto(s)

Anticuerpos Neutralizantes , Anticuerpos Antivirales , Disulfuros , Glicoproteínas Hemaglutininas del Virus de la Influenza , Vacunas contra la Influenza , Ratones Endogámicos BALB C , Infecciones por Orthomyxoviridae , Animales , Vacunas contra la Influenza/inmunología , Vacunas contra la Influenza/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/inmunología , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Glicoproteínas Hemaglutininas del Virus de la Influenza/química , Anticuerpos Antivirales/inmunología , Ratones , Disulfuros/química , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/virología , Anticuerpos Neutralizantes/inmunología , Femenino , Protección Cruzada/inmunología , Reacciones Cruzadas , Humanos , Gripe Humana/prevención & control , Gripe Humana/inmunología , Gripe Humana/virología , Epítopos/inmunología , Epítopos/genética , Epítopos/química , Multimerización de Proteína , Virus de la Influenza B/inmunología , Virus de la Influenza B/genética , Virus de la Influenza B/química

RESUMEN

Acute lung injury (ALI) arises from an excessive inflammatory response, usually progressing to acute respiratory distress syndrome (ARDS) if not promptly addressed. There is currently a limited array of effective treatments available for ALI. In this study, we developed disulfide bond-bridged prodrug self-assembled nanoparticles (referred to as DSSS NPs). These nanoparticles were consisted of Dexamethasone (Dex) and stearic acid (SA), and were designed to target and treat ALI. DSSS NPs demonstrated a substantial drug loading capacity with 37.75 % of Dex, which is much higher than conventional nanomedicines (usually < 10 %). Moreover, they exhibited the potential to specifically target injured lung tissue and inflammatory microenvironment-responsive release drugs. Consequently, DSSS NPs reduced significantly the levels of pro-inflammatory cytokines and tissue damage in mice with ALI induced by lipopolysaccharide (LPS). Overall, DSSS NPs offer a promising strategy for treatment of acute lung injury.

Asunto(s)

Lesión Pulmonar Aguda , Antiinflamatorios , Dexametasona , Disulfuros , Lipopolisacáridos , Nanopartículas , Oxidación-Reducción , Ácidos Esteáricos , Dexametasona/administración & dosificación , Dexametasona/química , Lesión Pulmonar Aguda/tratamiento farmacológico , Animales , Nanopartículas/química , Disulfuros/química , Ratones , Antiinflamatorios/administración & dosificación , Antiinflamatorios/química , Antiinflamatorios/farmacología , Ácidos Esteáricos/química , Masculino , Liberación de Fármacos , Citocinas/metabolismo , Profármacos/química , Profármacos/administración & dosificación , Humanos , Ratones Endogámicos C57BL , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Portadores de Fármacos/química

RESUMEN

Biomolecular condensates (BCs) are membraneless hubs enriched with proteins and nucleic acids that have emerged as important players in many cellular functions. Uncovering the sequence determinants of proteins for phase separation is essential in understanding the biophysical and biochemical properties of BCs. Despite significant discoveries in the past decade, the role of cysteine residues in BC formation and dissolution has remained unknown. Here, to uncover the involvement of disulfide cross-links and their redox sensitivity in BCs, we designed a "stickers and spacers" model of phase-separating peptides interspersed with cysteines. Through biophysical investigations, we learned that cysteines promote liquid-liquid phase separation in oxidizing conditions and perpetuate liquid condensates through disulfide cross-links, which can be reversibly tuned with redox chemistry. By varying the composition of cysteines, subtle but distinct changes in the viscoelastic behavior of the condensates were observed. Empirically, we conclude that cysteines function neither as stickers nor spacers but as covalent nodes to lower the effective concentrations for sticker interactions and inhibit system-spanning percolation networks. Together, we unmask the possible role of cysteines in the formation of biomolecular condensates and their potential use as tunable covalent cross-linkers in developing redox-sensitive viscoelastic materials.

Asunto(s)

Condensados Biomoleculares , Cisteína , Disulfuros , Disulfuros/química , Condensados Biomoleculares/química , Cisteína/química , Oxidación-Reducción , Péptidos/química , Reactivos de Enlaces Cruzados/química , Separación de Fases

RESUMEN

As artificial receptors for protein recognition, epitope-imprinted polymers combined with fluorescence sensing based on quantum dots (QDs) can be potentially used for biological analysis and disease diagnosis. However, the usual way for fabrication of QD sensors through unoriented epitope imprinting is confronted with the problems of disordered imprinting sites and low template utilization. In this context, a facile and efficient oriented epitope surface imprinting was put forward based on immobilization of the epitope templates via thiol-disulfide exchange reactions. With N-succinimidyl 3-(2-pyridyldithio)-propionate (SPDP) as a heterobifunctional reagent, cysteine-modified epitopes of cytochrome c were anchored on the surface of pyridyl disulfide functionalized silica nanoparticles sandwiching CdTe QDs. After surface imprinting via a sol-gel process, the epitope templates were removed from the surface-imprinted layers simply by reduction of the thiol-disulfide, affording oriented epitope-imprinted sites. By this method, the amount of epitope templates was only 1/20 of traditionally unoriented epitopes. The resulting sensors demonstrated significantly enhanced imprinting performance and high sensitivity, with the imprinting factor increasing from 2.6 to 3.9, and the limit of detection being 91 nM. Such epitope-oriented surface-imprinted method may offer a new design strategy for the construction of high-affinity protein recognition nanomaterials with fluorescence sensing.

Asunto(s)

Disulfuros , Epítopos , Impresión Molecular , Nanopartículas , Puntos Cuánticos , Dióxido de Silicio , Compuestos de Sulfhidrilo , Puntos Cuánticos/química , Dióxido de Silicio/química , Compuestos de Sulfhidrilo/química , Epítopos/química , Disulfuros/química , Nanopartículas/química , Propiedades de Superficie , Telurio/química , Fluorescencia , Espectrometría de Fluorescencia , Compuestos de Cadmio/química