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1.
J Neurochem ; 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37429595

RESUMO

Small molecules are being explored intensively for their applications as therapeutic molecules in the management of metabolic and neurological disorders. The natural small molecules can inhibit protein aggregation and underlying cellular pathogenesis of neurodegenerative diseases involving multi-factorial mechanisms of action. Certain natural small molecular inhibitors of pathogenic protein aggregation are highly efficient and have shown promising therapeutic potential. In the present study, Shikonin (SHK), a natural plant-based naphthoquinone has been investigated for its aggregation inhibition activity against α-synuclein (α-syn) and the neuroprotective potential in Caenorhabditis elegans (C. elegans). SHK significantly inhibited aggregation of α-syn at sub-stochiometric concentrations, delayed the linear lag phase and growth kinetics of seeded and unseeded α-syn aggregation. The binding of SHK to the C-terminus of α-syn maintained α-helical and disordered secondary structures with reduced beta-sheet content and complexity of aggregates. Further, in C. elegans transgenic PD models, SHK significantly reduced α-syn aggregation, improved locomotor activity and prevented dopaminergic (DA) neuronal degeneration, indicating the neuroprotective role of SHK. The present study highlights the potential of natural small molecules in the prevention of protein aggregation that may further be explored for their therapeutic efficacy in the management of protein aggregation and neurodegenerative diseases.

2.
Int J Mol Sci ; 23(21)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36361893

RESUMO

Consistently emerging variants and the life-threatening consequences of SARS-CoV-2 have prompted worldwide concern about human health, necessitating rapid and accurate point-of-care diagnostics to limit the spread of COVID-19. Still, However, the availability of such diagnostics for COVID-19 remains a major rate-limiting factor in containing the outbreaks. Apart from the conventional reverse transcription polymerase chain reaction, loop-mediated isothermal amplification-based (LAMP) assays have emerged as rapid and efficient systems to detect COVID-19. The present study aims to develop RT-LAMP-based assay system for detecting multiple targets in N, ORF1ab, E, and S genes of the SARS-CoV-2 genome, where the end-products were quantified using spectrophotometry, paper-based lateral-flow devices, and electrochemical sensors. The spectrophotometric method shows a LOD of 10 agµL-1 for N, ORF1ab, E genes and 100 agµL-1 for S gene in SARS-CoV-2. The developed lateral-flow devices showed an LOD of 10 agµL-1 for all four gene targets in SARS-CoV-2. An electrochemical sensor developed for N-gene showed an LOD and E-strip sensitivity of log 1.79 ± 0.427 pgµL-1 and log 0.067 µA/pg µL-1/mm2, respectively. The developed assay systems were validated with the clinical samples from COVID-19 outbreaks in 2020 and 2021. This multigene target approach can effectively detect emerging COVID-19 variants using combination of various analytical techniques at testing facilities and in point-of-care settings.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , Sensibilidade e Especificidade , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Diagnóstico Molecular/métodos , RNA Viral/genética
3.
Cell Mol Life Sci ; 74(4): 617-629, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27522545

RESUMO

Protein misfolding under stressful environmental conditions cause several cellular problems owing to the disturbed cellular protein homeostasis, which may further lead to neurological disorders like Parkinson's disease (PD), Alzheimer's disease (AD), Amyloid lateral sclerosis and Huntington disease (HD). The presence of cellular defense mechanisms like molecular chaperones and proteasomal degradation systems prevent protein misfolding and aggregation. Molecular chaperones plays primary role in preventing protein misfolding by mediating proper native folding, unfolding and refolding of the polypeptides along with vast number of cellular functions. In past few years, the understanding of molecular chaperone mechanisms has been expanded enormously although implementation to prevent protein aggregation diseases is still deficient. We in this review evaluated major classes of molecular chaperones and their mechanisms relevant for preventing protein aggregation, specific case of α-synuclein aggregation. We also evaluate the molecular chaperone function as a novel therapeutic approach and the chaperone inhibitors or activators as small molecular drug targets.


Assuntos
Proteínas de Choque Térmico/metabolismo , Doença de Parkinson/metabolismo , Agregação Patológica de Proteínas/metabolismo , Dobramento de Proteína , alfa-Sinucleína/metabolismo , Animais , Humanos , Doença de Parkinson/patologia , Agregação Patológica de Proteínas/patologia , Deficiências na Proteostase/metabolismo , Deficiências na Proteostase/patologia , alfa-Sinucleína/química
4.
Proc Natl Acad Sci U S A ; 110(18): 7199-204, 2013 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-23584019

RESUMO

Chaperonins are cage-like complexes in which nonnative polypeptides prone to aggregation are thought to reach their native state optimally. However, they also may use ATP to unfold stably bound misfolded polypeptides and mediate the out-of-cage native refolding of large proteins. Here, we show that even without ATP and GroES, both GroEL and the eukaryotic chaperonin containing t-complex polypeptide 1 (CCT/TRiC) can unfold stable misfolded polypeptide conformers and readily release them from the access ways to the cage. Reconciling earlier disparate experimental observations to ours, we present a comprehensive model whereby following unfolding on the upper cavity, in-cage confinement is not needed for the released intermediates to slowly reach their native state in solution. As over-sticky intermediates occasionally stall the catalytic unfoldase sites, GroES mobile loops and ATP are necessary to dissociate the inhibitory species and regenerate the unfolding activity. Thus, chaperonin rings are not obligate confining antiaggregation cages. They are polypeptide unfoldases that can iteratively convert stable off-pathway conformers into functional proteins.


Assuntos
Trifosfato de Adenosina/farmacologia , Biocatálise/efeitos dos fármacos , Chaperonina 60/metabolismo , Chaperonina com TCP-1/metabolismo , Peptídeos/metabolismo , Redobramento de Proteína/efeitos dos fármacos , Desdobramento de Proteína/efeitos dos fármacos , Animais , Apoproteínas/metabolismo , Bovinos , Chaperonina 10/metabolismo , Congelamento , Modelos Moleculares , Estrutura Quaternária de Proteína , Especificidade por Substrato/efeitos dos fármacos , Sus scrofa , Tiossulfato Sulfurtransferase/metabolismo
5.
J Biol Chem ; 288(29): 21399-21411, 2013 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-23737532

RESUMO

Structurally and sequence-wise, the Hsp110s belong to a subfamily of the Hsp70 chaperones. Like the classical Hsp70s, members of the Hsp110 subfamily can bind misfolding polypeptides and hydrolyze ATP. However, they apparently act as a mere subordinate nucleotide exchange factors, regulating the ability of Hsp70 to hydrolyze ATP and convert stable protein aggregates into native proteins. Using stably misfolded and aggregated polypeptides as substrates in optimized in vitro chaperone assays, we show that the human cytosolic Hsp110s (HSPH1 and HSPH2) are bona fide chaperones on their own that collaborate with Hsp40 (DNAJA1 and DNAJB1) to hydrolyze ATP and unfold and thus convert stable misfolded polypeptides into natively refolded proteins. Moreover, equimolar Hsp70 (HSPA1A) and Hsp110 (HSPH1) formed a powerful molecular machinery that optimally reactivated stable luciferase aggregates in an ATP- and DNAJA1-dependent manner, in a disaggregation mechanism whereby the two paralogous chaperones alternatively activate the release of bound unfolded polypeptide substrates from one another, leading to native protein refolding.


Assuntos
Trifosfato de Adenosina/farmacologia , Proteínas de Choque Térmico HSP110/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Desdobramento de Proteína/efeitos dos fármacos , Biocatálise/efeitos dos fármacos , Estabilidade Enzimática/efeitos dos fármacos , Proteínas de Choque Térmico HSP40/metabolismo , Humanos , Hidrólise/efeitos dos fármacos , Luciferases/metabolismo , Modelos Biológicos , Ligação Proteica/efeitos dos fármacos , Redobramento de Proteína/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Estrutura Quaternária de Proteína , Solubilidade , Especificidade por Substrato/efeitos dos fármacos , Temperatura , Tripsina/farmacologia
6.
J Cell Sci ; 125(Pt 21): 5073-83, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-22946053

RESUMO

Several metals and metalloids profoundly affect biological systems, but their impact on the proteome and mechanisms of toxicity are not fully understood. Here, we demonstrate that arsenite causes protein aggregation in Saccharomyces cerevisiae. Various molecular chaperones were found to be associated with arsenite-induced aggregates indicating that this metalloid promotes protein misfolding. Using in vivo and in vitro assays, we show that proteins in the process of synthesis/folding are particularly sensitive to arsenite-induced aggregation, that arsenite interferes with protein folding by acting on unfolded polypeptides, and that arsenite directly inhibits chaperone activity. Thus, folding inhibition contributes to arsenite toxicity in two ways: by aggregate formation and by chaperone inhibition. Importantly, arsenite-induced protein aggregates can act as seeds committing other, labile proteins to misfold and aggregate. Our findings describe a novel mechanism of toxicity that may explain the suggested role of this metalloid in the etiology and pathogenesis of protein folding disorders associated with arsenic poisoning.


Assuntos
Arsenitos/farmacologia , Proteínas de Choque Térmico/metabolismo , Dobramento de Proteína/efeitos dos fármacos , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Grânulos Citoplasmáticos/metabolismo , Proteínas de Choque Térmico/antagonistas & inibidores , Luciferases de Vaga-Lume/biossíntese , Chaperonas Moleculares/antagonistas & inibidores , Chaperonas Moleculares/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Recombinantes/biossíntese , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores
7.
Biofabrication ; 16(2)2024 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-38277689

RESUMO

Ligament tissues exhibit zone-specific anisotropic cell organization. The cells in ligament-proper are longitudinally oriented, whereas, the cells in epiligament are circumferentially oriented. Therefore, scaffolds developed to regenerate ligament tissues should possess adequate architectural features to govern ligament-mimetic bi-directional cell organization. The scaffold architectural features along with ligament-mimetic cell organization may ultimately yield neo-tissues with ligament-like extracellular matrix (ECM) structure and biomechanical properties. Towards this goal, we fabricated a silk/gelatin-based core-shell scaffold (csSG) with zone-specific anisotropic architectural features, wherein, the core of the scaffold possessed longitudinally aligned pores while the shell of the scaffold possessed parallel microgrooves that are aligned circumferentially around the surface of the scaffold. The ligament-mimetic architectural features significantly improved the mechanical properties of the scaffold. Moreover, architectural features of the csSG scaffold governed zone-specific anisotropic organization of cells. The cells in the core were longitudinally oriented as observed in the ligament-proper and the cells on the shell were circumferentially oriented as observed in epiligament. This bi-directional cell orientation partially mimicked the complex cellular network in native ligament tissue. Additionally, both the core and the shell individually supported fibrogenic differentiation of stem cells which further improved their potential for ligament tissue engineering. Further, the aligned pores of the core could govern unidirectional organization of ECM deposited by cells which is crucial for regenerating anisotropic tissues like ligaments. Finally, when implanted subcutaneously in mice, the scaffolds retained their anisotropic architecture for at least 2 weeks, were biocompatible, supported cell infiltration and governed anisotropic organization of cells and ECM. Taken together, the fabricated biomimetic csSG scaffold, through its zone-specific architectural features, could govern ligament-mimetic cellular and ECM organization which is ultimately expected to achieve regeneration of ligament tissues with native-like hierarchical structure and biomechanical properties. Consequently, this study introduces bi-directional structural parameters as design criteria for developing scaffolds for ligament tissue engineering.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Animais , Camundongos , Alicerces Teciduais/química , Biomimética , Seda/química , Ligamentos
8.
Biofabrication ; 16(2)2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38471166

RESUMO

Scaffolds for bone tissue engineering should enable regeneration of bone tissues with its native hierarchically organized extracellular matrix (ECM) and multiple tissue interfaces. To achieve this, inspired by the structure and properties of bone osteon, we fabricated polyhydroxybutyrate (PHB)-based mineralized electrospun fibrous scaffolds. After studying multiple PHB-based fibers, we chose 7%PHB/1%Gelatin fibers (PG) to fabricate mineralized fibers that mimic mineralized collagen fibers in bone. The mineralized PG (mPG) surface had a rough, hydrophilic layer of low crystalline calcium phosphate which was biocompatible to bone marrow stromal cells (BMSCs), induced their proliferation and was osteoinductive. Subsequently, by modulating the electrospinning process, we fabricated mPG-based novel higher order fibrous scaffolds that mimic the macroscale geometries of osteons of bone ECM. Inspired by the aligned collagen fibers in bone lamellae, we fabricated mPG scaffolds with aligned fibers that could direct anisotropic elongation of mouse BMSC (mBMSCs). Further, we fabricated electrospun mPG-based osteoinductive tubular constructs which can mimic cylindrical bone components like osteons or lamellae or be used as long bone analogues based on their dimensions. Finally, to regenerate tissue interfaces in bone, we introduced a novel bi-layered scaffold-based approach. An electrospun bi-layered tubular construct that had PG in the outer layer and 7%PHB/0.5%Polypyrrole fibers (PPy) in the inner layer was fabricated. The bi-layered tubular construct underwent preferential surface mineralization only on its outer layer. This outer mineralized layer supported osteogenesis while the inner PPy layer could support neural cell growth. Thus, the bi-layered tubular construct may be used to regenerate haversian canal in the osteons which hosts nerve fibers. Overall, the study introduced novel techniques to fabricate biomimetic structures that can regenerate components of bone osteon and its multiple tissue interfaces. The study lays foundation for the fabrication of a modular scaffold that can regenerate bone with its hierarchical structure and complex tissue interfaces.


Assuntos
Engenharia Tecidual , Alicerces Teciduais , Camundongos , Animais , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Ósteon , Polímeros , Poli-Hidroxibutiratos , Poliésteres/química , Pirróis , Osso e Ossos , Colágeno
9.
Anal Methods ; 16(19): 3131-3141, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38712986

RESUMO

Plastics are ubiquitous in today's lifestyle, and their indiscriminate use has led to the accumulation of plastic waste in landfills and oceans. The waste accumulates and breaks into micro-particles that enter the food chain, causing severe threats to human health, wildlife, and the ecosystem. Environment-friendly and bio-based degradable materials offer a sustainable alternative to the vastly used synthetic materials. Here, a polylactic acid and carbon nanofiber-based membrane and a paper-based colorimetric sensor have been developed. The membrane had a surface area of 3.02 m2 g-1 and a pore size of 18.77 nm. The pores were evenly distributed with a pore volume of 0.0137 cm3 g-1. The membrane was evaluated in accordance with OECD guidelines and was found to be safe for tested aquatic and terrestrial models. The activated PLA-CNF membrane was further used as a bio-based electrode for the electrochemical detection of nitrates (NO3-) in water samples with a detection limit of 0.046 ppm and sensitivity of 1.69 × 10-4 A ppm-1 mm-2, whereas the developed paper-based colorimetric sensor had a detection limit of 156 ppm for NO3-. This study presents an environment-friendly, low-carbon footprint disposable material for sensing applications as a sustainable alternative to plastics.


Assuntos
Carbono , Colorimetria , Nanofibras , Nitratos , Papel , Poliésteres , Nanofibras/química , Colorimetria/métodos , Colorimetria/instrumentação , Nitratos/análise , Nitratos/química , Poliésteres/química , Carbono/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Limite de Detecção , Poluentes Químicos da Água/análise , Condutividade Elétrica , Membranas Artificiais
10.
Food Chem (Oxf) ; 8: 100200, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-38525270

RESUMO

Meat adulteration and admixing are prevalent malpractices observed in processed and raw meat samples, where the consumption of adulterated meat has been associated with food allergies, financial losses, and consumer distrust. Meat authentication is pivotal to address these concerns. The meat authenticity can be determined through genetic, protein, and immunological markers and advanced detection methods. However, these methods often target a single species and lack the specificity to distinguish closely related species. Here, in the present study, we have developed a multiplex detection method based on the species-specific primers and probes, that can target four meat species in one reaction. The developed method amplifies the mitochondrial genomic regions of chicken, pork, sheep and goat using TaqMan multiplex probe-based RT-qPCR assay. Unique pairs of species-specific primers and probes that target specific mitochondrial DNA (mtDNA) regions of each species were designed and screened for specificity and sensitivity. The detection limit for species identification using the designed primers in real-time qPCR assays was 0.1 picogram per microliter (pg/µL) DNA detected in singleplex reaction and facilitates the simultaneous detection of closely related species, such as goat and sheep. Further, DNA-based probes were utilized in a multiplex real-time qPCR assay to identify chicken, pork, sheep and goat DNA in a single tube reaction. The multiplex assay was validated for raw and processed meat products, demonstrating its applications in ensuring the quality of meat products and safeguarding consumer interests.

11.
Food Chem ; 401: 134180, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36115229

RESUMO

The use of biopolymers is gaining momentum owing to their compatibility with various food commodities and acceptability by the industry and consumers. Biopolymers integrated with natural pigments can be used for assessing the quality of perishable packaged food products. Here, a biodegradable composite membrane of starch and chitosan, integrated with anthocyanin has been developed. The chromogenic response of the developed biocomposite membrane was used to assess spoilage in milk. The surface roughness recorded using atomic force microscopy and scanning electron microscopy showed smooth membrane surface, and a pore size 4.21 nm was determined by Brunauer-Emmett-Teller analysis. The water vapour transmissibility of the membrane was 4.616E-09 and 1.147E-08 g/h Pa.mm and water solubility was 5.6 and 5.8 % at 25 and 37 ℃, respectively, indicating high water resistance and low vapour transmission rate. The developed biocomposite membrane offers an environment friendly substrate for biosensing with a promising potential in smart food-packaging applications.


Assuntos
Quitosana , Vapor , Antocianinas , Embalagem de Alimentos , Amido , Qualidade dos Alimentos
12.
Mol Neurobiol ; 60(6): 3277-3298, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36828952

RESUMO

The ubiquitin-proteasome system (UPS) controls protein homeostasis to maintain cell functionality and survival. Neurogenesis relies on proteasome function, and a defective proteasome system during brain development leads to neurological disorders. An endocrine-disrupting xenoestrogen bisphenol-A (BPA) used in plastic products adversely affects human health and causes neurotoxicity. Previously, we reported that BPA reduces neural stem cells (NSCs) proliferation and differentiation, impairs myelination and mitochondrial protein import, and causes excessive mitochondrial fragmentation leading to cognitive impairments in rats. Herein, we examined the effect(s) of prenatal BPA exposure on UPS functions during NSCs proliferation and differentiation in the hippocampus. Rats were orally treated with 40 µg/kg body weight BPA during day 6 gestation to day 21 postnatal. BPA significantly reduced proteasome activity in a cellular extract of NSCs. Immunocytochemistry exhibited a significant reduction of 20S proteasome/Nestin+ and PSMB5/Nestin+ cells in NSCs culture. BPA decreased 20S/Tuj1+ and PSMB5/Tuj1+ cells, indicating disrupted UPS during neuronal differentiation. BPA reduced the expression of UPS genes, 20S, and PSMB5 protein levels and proteasome activity in the hippocampus. It significantly reduced overall protein synthesis by the loss of Nissl substances in the hippocampus. Pharmacological activation of UPS by a bioactive triterpenoid 18α-glycyrrhetinic acid (18α GA) caused increased proteasome activities, significantly increased neurosphere size and number, and enhanced NSCs proliferation in BPA exposed culture, while proteasome inhibition by MG132 further aggravates BPA-mediated effects. In silico studies demonstrated that BPA strongly binds to catalytic sites of UPS genes (PSMB5, TRIM11, Parkin, and PSMD4) which may result in UPS inactivation. These results suggest that BPA significantly reduces NSCs proliferation by impairing UPS, and UPS activation by 18α GA could suppress BPA-mediated neurotoxicity and exerts neuroprotection.


Assuntos
Complexo de Endopeptidases do Proteassoma , Ubiquitina , Gravidez , Feminino , Animais , Ratos , Humanos , Complexo de Endopeptidases do Proteassoma/metabolismo , Nestina/metabolismo , Ubiquitina/metabolismo , Neurogênese , Hipocampo/metabolismo , Compostos Benzidrílicos/toxicidade , Proteínas com Motivo Tripartido/metabolismo , Proteínas com Motivo Tripartido/farmacologia , Ubiquitina-Proteína Ligases/metabolismo
13.
Carbohydr Polym ; 302: 120368, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36604048

RESUMO

The rapidly growing electronic and plastic waste has become a global environmental concern. Developing advanced and environmentally safe agro-based materials is an emerging field with an enormous potential for applications in sensors and devices. Here, an agro-based material as membrane has been developed by incorporating tapioca starch and banana peel powder in polylactic acid, with uniform dispersibility and amorphous nature. The material was used for the development of electrochemical sensor for S-gene of SARS-CoV-2. Further, the membrane was used for the development of a non-invasive, colorimetric skin patch for the detection of glucose and a sensor for the assessment of fruit juice quality. Using OECD-recommended model systems, the developed membrane was found to be non-toxic towards aquatic and terrestrial non-target organisms. The developed conductive material opens new avenues in various electrochemical, analytical, and biological applications.


Assuntos
Técnicas Biossensoriais , COVID-19 , Manihot , Musa , Musa/química , Colorimetria , COVID-19/diagnóstico , SARS-CoV-2 , Amido/química
14.
ACS Chem Neurosci ; 14(17): 3103-3112, 2023 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-37562012

RESUMO

Post-translational modifications guide the functional diversity and identity of proteins. Phosphorylation is one such post-translational modification that has been reported in pathological proteins related to various neurodegenerative disorders such as α-synuclein (α-syn) phosphorylation in Parkinson's disease and other synucleinopathies. In α-syn, the phosphorylation has mostly been observed at S129; however, the occurrence of other serine modifications at S9, S42, and S87 is partially explored. In pathogenic conditions, where α-syn is phosphorylated by complex kinase pathways, multi-site modifications may happen and alter the mechanism of α-syn aggregation. Here, using Polo-like kinase 2 and G-protein coupled receptor kinase 4, the in vitro phosphorylation of α-syn was performed, which revealed multi-serine phosphorylation. Mass spectrometry with customized proteolytic digestion showed prominent phosphorylation at S129 and modifications at S87 and S42 with PLK2 and S87 with GRK4. The phosphorylation at the identified serine residues was further validated with NMR and western blotting. Multi-serine phosphorylation aggravates the aggregation potential of monomeric α-syn, seeding capacity, and cytotoxicity in the SH-SY5Y cell line. This study proposes evidence for in vitro multi-site phosphorylation and its significance in α-syn aggregation, toxicity, and related pathogenesis.


Assuntos
Neuroblastoma , Doença de Parkinson , Humanos , alfa-Sinucleína/metabolismo , Fosforilação , Serina/metabolismo , Doença de Parkinson/metabolismo
15.
J Biochem ; 173(2): 107-114, 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36368019

RESUMO

The accumulation of protein aggregates as intracellular inclusions interferes with cellular protein homeostasis leading to protein aggregation diseases. Protein aggregation results in the formation of several protein conformers including oligomers and fibrils, where each conformer has its own structural characteristic and proteotoxic potential. The present study explores the effect of alpha-synuclein (α-syn) conformers on the activity and spontaneous refolding of firefly luciferase. Of the different conformers, α-syn monomers delayed the inactivation of luciferase under thermal stress conditions and enhanced the spontaneous refolding of luciferase. In contrast, the α-syn oligomers and fibrils adversely affected luciferase activity and refolding, where the oligomers inhibited spontaneous refolding, whereas a pronounced effect on the inactivation of native luciferase was observed in the case of fibrils. These results indicate that the oligomers and fibrils of α-syn interfere with the refolding of luciferase and promote its misfolding and aggregation. The study reveals the differential propensities of various conformers of a pathologically relevant protein in causing inactivation, structural modifications and misfolding of other proteins, consequently resulting in altered protein homeostasis.


Assuntos
alfa-Sinucleína , Humanos , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , Doença de Parkinson/metabolismo , Agregados Proteicos , Dobramento de Proteína , Vaga-Lumes , Luciferases/química , Luciferases/metabolismo
16.
Food Chem ; 418: 135965, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37018903

RESUMO

Bioelectrodes with low carbon footprint can provide an innovative solution to the surmounting levels of e-waste. Biodegradable polymers offer green and sustainable alternatives to synthetic materials. Here, a chitosan-carbon nanofiber (CNF) based membrane has been developed and functionalized for electrochemical sensing application. The surface characterization of the membrane revealed crystalline structure with uniform particle distribution, and surface area of 25.52 m2/g and pore volume of 0.0233 cm3/g. The membrane was functionalized to develop a bioelectrode for the detection of exogenous oxytocin in milk. Electrochemical impedance spectroscopy was employed to determine oxytocin in a linear concentration range of 10 to 105 ng/mL. The developed bioelectrode showed an LOD of 24.98 ± 11.37 pg/mL and sensitivity of 2.77 × 10-10 Ω / log ng mL-1/mm2 for oxytocin in milk samples with 90.85-113.34 percent recovery. The chitosan-CNF membrane is ecologically safe and opens new avenues for environment-friendly disposable materials for sensing applications.


Assuntos
Técnicas Biossensoriais , Quitosana , Nanofibras , Carbono/química , Quitosana/química , Ocitocina/química , Eletrodos , Técnicas Biossensoriais/métodos
17.
Toxicology ; 465: 153049, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34818560

RESUMO

The adverse physiological conditions have been long known to impact protein synthesis, folding and functionality. Major physiological factors such as the effect of pH, temperature, salt and pressure are extensively studied for their impact on protein structure and homeostasis. However, in the current scenario, the environmental risk factors (pollutants) have gained impetus in research because of their increasing concentrations in the environment and strong epidemiologic link with protein aggregation disorders. Here, we review the physiological and environmental risk factors for their impact on protein conformational changes, misfolding, aggregation, and associated pathological conditions, especially environmental risk factors associated pathologies.


Assuntos
Poluentes Ambientais/efeitos adversos , Proteínas/metabolismo , Deficiências na Proteostase/induzido quimicamente , Animais , Exposição Ambiental/efeitos adversos , Humanos , Agregados Proteicos , Agregação Patológica de Proteínas , Dobramento de Proteína , Estrutura Terciária de Proteína , Proteínas/química , Proteostase , Deficiências na Proteostase/metabolismo , Deficiências na Proteostase/patologia , Medição de Risco , Fatores de Risco , Estresse Fisiológico , Relação Estrutura-Atividade
18.
ACS Appl Mater Interfaces ; 14(8): 10167-10186, 2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35171571

RESUMO

Bioengineering an in vitro liver model recapitulating the native liver microarchitecture consisting of parenchymal and non-parenchymal cells is crucial in achieving cellular crosstalk and hepatic metabolic functions for accurate hepatotoxicity prediction. Bioprinting holds the promise of engineering constructs with precise control over the spatial distribution of multiple cells. Two distinct tissue-specific liver extracellular matrix (ECM)-based bioinks with excellent printability and rheological attributes are formulated for supporting parenchymal and non-parenchymal cells. A physiologically relevant human vascularized liver model is bioprinted with a novel liver ECM-based bioink laden with human adipose mesenchymal stem cell-derived hepatocyte-like cells (HLCs), human umbilical vein endothelial cells (HUVECs), and human hepatic stellate cells (HHSCs) using an extrusion-based bioprinting approach and validated for hepatotoxicity assessment. The HLC/HUVEC/HHSC-laden liver model resembles native alternate cords of hepatocytes with a functional sinusoidal lumen-like network in both horizontal and vertical directions, demonstrating enhanced albumin production, urea synthesis, and cytochrome P450 (CPR) activity. Furthermore, the liver model is evaluated for drug toxicity assessment following 24 h exposure to different concentrations of (i) non-hepatotoxicants aspirin and dexamethasone, (ii) idiosyncratic hepatotoxicant trovafloxacin mesylate, and (iii) clinical hepatotoxicant acetaminophen and troglitazone. A follow-up cell viability and metabolic competence evaluation by estimating DNA concentration, lactate dehydrogenase activity, and CPR activity revealed a dose-dependent clinically relevant hepatotoxic response. These results corroborated that the developed clinically relevant vascularized liver model is affordable and would aid pharmaceutical companies in speeding up the drug development and provide a robust platform for hepatotoxicity screening.


Assuntos
Bioimpressão , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Bioimpressão/métodos , Avaliação Pré-Clínica de Medicamentos , Células Endoteliais , Humanos , Fígado , Impressão Tridimensional , Engenharia Tecidual/métodos , Alicerces Teciduais
19.
Nanomaterials (Basel) ; 12(7)2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35407332

RESUMO

Engineered nanoparticles (ENPs) are artificially synthesized particles with unique physicochemical properties. ENPs are being extensively used in several consumer items, elevating the probability of ENP exposure to biological systems. ENPs interact with various biomolecules like lipids, proteins, nucleic acids, where proteins are most susceptible. The ENP-protein interactions are mostly studied for corona formation and its effect on the bio-reactivity of ENPs, however, an in-depth understanding of subsequent interactive effects on proteins, such as alterations in their structure, conformation, free energy, and folding is still required. The present review focuses on ENP-protein interactions and the subsequent effects on protein structure and function followed by the therapeutic potential of ENPs for protein misfolding diseases.

20.
Bioresour Technol ; 325: 124739, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33509643

RESUMO

The progression of plastic pollution is a global concern. "Reuse, reduce and recycle" offers a solution to the burdening issue, although not enough to curb the rampant use of plastics. Biodegradable plastics are gaining acceptability in agriculture and food packaging industries; nevertheless, they occupy a rather small section of the plastic market. This review summarizes recent advances in the development of biodegradable plastics and their safe degradation potentials. Here, biodegradable plastics have been categorized and technology and developments in the field of biopolymers, their applicability, degradation and role in sustainable development has been reviewed. Also, the use of natural polymers with improved mechanical and physical properties that brings them at par with their counterparts has been discussed. Biodegradable polymers add value to the industries that would help in achieving sustainable development and consequently reinforce green economy, reducing the burden of greenhouse gases in the environment and valorisation of waste biomass.


Assuntos
Plásticos Biodegradáveis , Polímeros , Biodegradação Ambiental , Biopolímeros , Plásticos , Reciclagem
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