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3.
J Mater Chem B ; 12(26): 6442-6451, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38860876

RESUMO

Self-assembled DNA nanostructures hold great promise in biosensing, drug delivery and nanomedicine. Nevertheless, challenges like instability and inefficiency in cellular uptake of DNA nanostructures under physiological conditions limit their practical use. To tackle these obstacles, this study proposes a novel approach that integrates the cationic polymer polyethyleneimine (PEI) with DNA self-assembly. The hypothesis is that the positively charged linear PEI can facilitate the self-assembly of DNA nanostructures, safeguard them against harsh conditions and impart them with the cellular penetration characteristic of PEI. As a demonstration, a DNA nanotube (PNT) was successfully synthesized through PEI mediation, and it exhibited significantly enhanced stability and cellular uptake efficiency compared to conventional Mg2+-assembled DNA nanotubes. The internalization mechanism was further found to be both clathrin-mediated and caveolin-mediated endocytosis, influenced by both PEI and DNA. To showcase the applicability of this hybrid nanostructure for biomedical settings, the KRAS siRNA-loaded PNT was efficiently delivered into lung adenocarcinoma cells, leading to excellent anticancer effects in vitro. These findings suggest that the PEI-mediated DNA assembly could become a valuable tool for future biomedical applications.


Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Nanotubos , Polietilenoimina , Proteínas Proto-Oncogênicas p21(ras) , RNA Interferente Pequeno , Humanos , Células A549 , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/patologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , DNA/química , Portadores de Fármacos/química , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Nanotubos/química , Tamanho da Partícula , Polietilenoimina/química , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , RNA Interferente Pequeno/química , RNA Interferente Pequeno/farmacologia
4.
Sci Data ; 11(1): 625, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38871800

RESUMO

Recent research in computational imaging largely focuses on developing machine learning (ML) techniques for image recognition in the medical field, which requires large-scale and high-quality training datasets consisting of raw images and annotated images. However, suitable experimental datasets for cervical spine X-ray are scarce. We fill the gap by providing an open-access Cervical Spine X-ray Atlas (CSXA), which includes 4963 raw PNG images and 4963 annotated images with JSON format (JavaScript Object Notation). Every image in the CSXA is enriched with gender, age, pixel equivalent, asymptomatic and symptomatic classifications, cervical curvature categorization and 118 quantitative parameters. Subsequently, an efficient algorithm has developed to transform 23 keypoints in images into 77 quantitative parameters for cervical spine disease diagnosis and treatment. The algorithm's development is intended to assist future researchers in repurposing annotated images for the advancement of machine learning techniques across various image recognition tasks. The CSXA and algorithm are open-access with the intention of aiding the research communities in experiment replication and advancing the field of medical imaging in cervical spine.


Assuntos
Algoritmos , Vértebras Cervicais , Aprendizado de Máquina , Humanos , Vértebras Cervicais/diagnóstico por imagem , Radiografia , Masculino , Feminino
5.
Nature ; 631(8020): 393-401, 2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-38776962

RESUMO

AMPylation is a post-translational modification in which AMP is added to the amino acid side chains of proteins1,2. Here we show that, with ATP as the ligand and actin as the host activator, the effector protein LnaB of Legionella pneumophila exhibits AMPylase activity towards the phosphoryl group of phosphoribose on PRR42-Ub that is generated by the SidE family of effectors, and deubiquitinases DupA and DupB in an E1- and E2-independent ubiquitination process3-7. The product of LnaB is further hydrolysed by an ADP-ribosylhydrolase, MavL, to Ub, thereby preventing the accumulation of PRR42-Ub and ADPRR42-Ub and protecting canonical ubiquitination in host cells. LnaB represents a large family of AMPylases that adopt a common structural fold, distinct from those of the previously known AMPylases, and LnaB homologues are found in more than 20 species of bacterial pathogens. Moreover, LnaB also exhibits robust phosphoryl AMPylase activity towards phosphorylated residues and produces unique ADPylation modifications in proteins. During infection, LnaB AMPylates the conserved phosphorylated tyrosine residues in the activation loop of the Src family of kinases8,9, which dampens downstream phosphorylation signalling in the host. Structural studies reveal the actin-dependent activation and catalytic mechanisms of the LnaB family of AMPylases. This study identifies, to our knowledge, an unprecedented molecular regulation mechanism in bacterial pathogenesis and protein phosphorylation.


Assuntos
Monofosfato de Adenosina , Proteínas de Bactérias , Legionella pneumophila , Fosfotirosina , Transdução de Sinais , Humanos , Actinas/metabolismo , Monofosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , ADP-Ribosilação , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Hidrólise , Legionella pneumophila/enzimologia , Legionella pneumophila/metabolismo , Legionella pneumophila/patogenicidade , Ligantes , Modelos Moleculares , N-Glicosil Hidrolases/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Tirosina/metabolismo , Tirosina/química , Ubiquitina/metabolismo , Ubiquitinação , Enzimas Desubiquitinantes/metabolismo , Dobramento de Proteína , Fosfotirosina/química , Fosfotirosina/metabolismo
7.
Front Bioeng Biotechnol ; 12: 1337808, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38681963

RESUMO

Introduction: Magnetic Resonance Imaging (MRI) is essential in diagnosing cervical spondylosis, providing detailed visualization of osseous and soft tissue structures in the cervical spine. However, manual measurements hinder the assessment of cervical spine sagittal balance, leading to time-consuming and error-prone processes. This study presents the Pyramid DBSCAN Simple Linear Iterative Cluster (PDB-SLIC), an automated segmentation algorithm for vertebral bodies in T2-weighted MR images, aiming to streamline sagittal balance assessment for spinal surgeons. Method: PDB-SLIC combines the SLIC superpixel segmentation algorithm with DBSCAN clustering and underwent rigorous testing using an extensive dataset of T2-weighted mid-sagittal MR images from 4,258 patients across ten hospitals in China. The efficacy of PDB-SLIC was compared against other algorithms and networks in terms of superpixel segmentation quality and vertebral body segmentation accuracy. Validation included a comparative analysis of manual and automated measurements of cervical sagittal parameters and scrutiny of PDB-SLIC's measurement stability across diverse hospital settings and MR scanning machines. Result: PDB-SLIC outperforms other algorithms in vertebral body segmentation quality, with high accuracy, recall, and Jaccard index. Minimal error deviation was observed compared to manual measurements, with correlation coefficients exceeding 95%. PDB-SLIC demonstrated commendable performance in processing cervical spine T2-weighted MR images from various hospital settings, MRI machines, and patient demographics. Discussion: The PDB-SLIC algorithm emerges as an accurate, objective, and efficient tool for evaluating cervical spine sagittal balance, providing valuable assistance to spinal surgeons in preoperative assessment, surgical strategy formulation, and prognostic inference. Additionally, it facilitates comprehensive measurement of sagittal balance parameters across diverse patient cohorts, contributing to the establishment of normative standards for cervical spine MR imaging.

8.
PeerJ ; 12: e16817, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38515460

RESUMO

Background: Antibody-based platforms (i.e., ADC) have emerged as one of the most encouraging tools for the cancer resistance caused by cancer stem cells (CSCs) enrichment. Our study might provide a promising therapeutic direction against drug resistance and serve as a potential precursor platform for screening ADC. Methods: The cell migration, invasion, drug resistance, and self-renewal were assessed by the cell invasion and migration assay, wound healing assay, CCK-8 assay, colony formation assay, and sphere formation assay, respectively. The expression profiles of CSCs (ALDH+ and CD44+) subpopulations were screened by flow cytometry. The western blot and cell immunofluorescence assay were used to evaluate pathway-related protein expression in both anti-ENO1 antibody, MET combined with DPP/CTX-treated CSCs. Results: In the present study, western blot and flow cytometry verified that anti-ENO1 antibody target the CD44+ subpopulation by inhibiting the PI3K/AKT pathway, while metformin might target the ALDH+ subpopulation through activation of the AMPK pathway and thus reverse drug resistance to varying degrees. Subsequently, in vitro investigation indicated that anti-ENO1 antibody, metformin combined with cisplatin/cetuximab could simultaneously target ALDH+ and CD44+ subpopulations. The combination also inhibited the CSCs proliferation, migration, invasion, and sphere formation; which may result in overcoming the drug resistance. Then, molecular mechanism exploration verified that the anti-ENO1 antibody, metformin combined with cisplatin/cetuximab inhibited the Wnt/ß-catenin signaling. Conclusions: The study preliminarily revealed anti-ENO1 antibody combined with metformin could overcome drug resistance against CSCs by inhibiting the Wnt//ß-catenin pathway and might serve as a potential precursor platform for screening ADC. More importantly, it is reasonably believed that antibody-based drug combination therapy might function as an encouraging tool for oncotherapy.


Assuntos
Metformina , Metformina/farmacologia , Cisplatino/farmacologia , beta Catenina/metabolismo , Linhagem Celular Tumoral , Cetuximab , Fosfatidilinositol 3-Quinases/metabolismo
9.
Nanoscale ; 16(4): 1983-1998, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38189459

RESUMO

Acute lung injury (ALI) is an inflammatory disease caused by multiple factors such as infection, trauma, and chemicals. Without effective intervention during the early stages, it usually quickly progresses to acute respiratory distress syndrome (ARDS). Since ordinary pharmaceutical preparations cannot precisely target the lungs, their clinical application is limited. In response, we constructed a γ3 peptide-decorated and ROS-responsive nanoparticle system encapsulating therapeutic dexamethasone (Dex/PSB-γ3 NPs). In vitro, Dex/PSB-γ3 NPs had rapid H2O2 responsiveness, low cytotoxicity, and strong intracellular ROS removal capacity. In a mouse model of ALI, Dex/PSB-γ3 NPs accumulated at the injured lung rapidly, alleviating pulmonary edema and cytokine levels significantly. The modification of NPs by γ3 peptide achieved highly specific positioning of NPs in the inflammatory area. The ROS-responsive release mechanism ensured the rapid release of therapeutic dexamethasone at the inflammatory site. This combined approach improves treatment accuracy, and drug bioavailability, and effectively inhibits inflammation progression. Our study could effectively reduce the risk of ALI progressing to ARDS and hold potential for the early treatment of ALI.


Assuntos
Lesão Pulmonar Aguda , Nanopartículas , Síndrome do Desconforto Respiratório , Camundongos , Animais , Espécies Reativas de Oxigênio/farmacologia , Molécula 1 de Adesão Intercelular , Peróxido de Hidrogênio/uso terapêutico , Lesão Pulmonar Aguda/tratamento farmacológico , Pulmão , Síndrome do Desconforto Respiratório/tratamento farmacológico , Nanopartículas/uso terapêutico , Peptídeos/farmacologia , Peptídeos/uso terapêutico , Dexametasona/farmacologia , Dexametasona/uso terapêutico
10.
Org Biomol Chem ; 22(6): 1186-1193, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38214570

RESUMO

An azido-radical-triggered cyclization of N-(o-cyanobiaryl)acrylamides with TMSN3via a C(sp3)-N/C(sp2)-C(sp3)/C(sp2)-N bond formation cascade is described. This reaction features mild conditions and high bond-forming efficiency, making it an efficient method for the construction of azide-substituted pyridophenanthridines.

11.
Org Lett ; 25(40): 7412-7416, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37788358

RESUMO

A visible-light-promoted cascade cyclization of 3-ethynyl-[1,1'-biphenyl]-2-carbonitriles with unsaturated α-bromocarbonyls for the synthesis of tetrahydrobenzo[mn]cyclopenta[b]acridines is described. Three C(sp3)-C(sp2) bonds, one C(sp2)-N bond, and three cycles can be formed in a single reaction through the addition of a C-centered radical to the carbon-carbon triple bond and three radical cyclizations. This reaction features mild conditions, wide substrate scope, and high bond-forming efficiency.

12.
Stem Cell Res Ther ; 14(1): 273, 2023 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-37759328

RESUMO

BACKGROUND: Identification of promising targeted antigens that exhibited cancer-specific expression is a crucial step in the development of novel antibody-targeted therapies. We here aimed to investigate the anti-tumor activity of a novel monoclonal antibody (mAb) 11C9 and identify the antibody tractable target in the hepatocellular cancer stem cells (HCSCs). METHODS: The identification of the targeted antigen was conducted using SDS-PAGE, western blot, mass spectrometry, and co-immunoprecipitation. Silence of HSP90 was induced by siRNA interference. Positive cells were sorted by fluorescence-activated cell sorting. Double-immunofluorescent (IF) staining and two-color flow cytometry detected the co-expression. Self-renewal, invasion, and drug resistance were assessed by sphere formation, matrigel-coated Transwell assay, and CCK-8 assay, respectively. Tumorigenicity was evaluated in mouse xenograft models. RNA-seq and bioinformatics analysis were performed to explore the mechanism of mAb 11C9 and potential targets. RESULTS: MAb 11C9 inhibited invasion and self-renewal abilities of HCC cell lines and reversed the cisplatin resistance. HSP90 (~ 95 kDa) was identified as a targeted antigen of mAb 11C9. Tissue microarrays and online databases revealed that HSP90 was overexpressed in HCC and associated with a poor prognosis. FACS and double-IF staining showed the co-expression of HSP90 and CSCs markers (CD90 and ESA). In vitro and in vivo demonstrated the tumorigenic potentials of HSP90. The inhibition of HSP90 by siRNA interference or 17-AAG inhibitor both decreased the number of invasion, sphere cells, and CD90+ or ESA+ cells, as well as reversed the resistance. Bioinformatics analysis and western blot verified that HSP90 activated Wnt/ß-catenin signaling. CONCLUSIONS: The study preliminarily revealed the anti-tumor activity of mAb 11C9. More importantly, we identified HSP90 as a targeted antigen of mAb 11C9, which functions as an oncogene in phenotype shaping, stemness maintenance, and therapeutic resistance by activating Wnt/ß-catenin signaling.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Camundongos , Humanos , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , beta Catenina/metabolismo , Linhagem Celular Tumoral , RNA Interferente Pequeno/metabolismo , Modelos Animais de Doenças , Células-Tronco Neoplásicas/metabolismo , Proliferação de Células
13.
J Org Chem ; 88(17): 12727-12737, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37596973

RESUMO

Imidazolinones were obtained in good yields by intramolecular hydroamination of N-alkoxy ureas in the presence of an organic photocatalyst and an inorganic base. In this reaction, the N-alkoxy urea anion generated by deprotonation undergoes photocatalyzed single-electron-transfer oxidation to generate the corresponding radical, which cyclizes to afford the imidazolinone ring. This new protocol grants access to an array of complex molecules containing a privileged imidazolinone core.

14.
J Colloid Interface Sci ; 651: 645-658, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37562306

RESUMO

The introduction of nitrogen vacancies into polymeric carbon nitride (PCN) has been attested to be a reliable strategy to enhance photocatalytic performance. Nitrogen vacancies were considered as active sites to promote the adsorption of target molecules and capture photoexcited electrons to inhibit the recombination of charge pairs, accelerate photoinduced electrons to participate in photocatalytic reaction. In this paper, a series of PCN with rich nitrogen vacancies were prepared by etching of chromic acid solution. Sample 20KCSCN had the highest photocatalytic performance whose evolution efficiency of CO2 to CO and CH4 can reach 3.9 and 0.5 µmol·g-1·h-1, respectively. These evolution efficiencies are 2.9 and 4 times higher than that of the PCN. Meanwhile, 20KCSCN demonstrates high CO conversion selectivity and stability. The successful introduction of nitrogen vacancies not only increases the active sites of PCN surface, but also optimizes the optical structure, which dramatically boosts the separation of photoexcited charge pairs and the reduction capacity of photogenerated electrons. The enhancement mechanism for photocatalytic CO2 reduction performance of PCN was proposed. Besides, photocatalytic H2 evolution experiments were performed on all samples to confirm the universality of PCN photocatalytic activity enhancement etched by chromic acid solution. H2 evolution rate on 20KCSCN can reach 652 µmol·g-1·h-1, which is 1.6-fold higher than that on PCN (254 µmol·g-1·h-1) after 4 h irradiation under a 300 W Xe lamp. This work offers new venue for introducing nitrogen vacancies in PCN to regulate photoexcited charge pairs transfer. The photocatalytic enhancement of CO2 reduction could be used to alleviate the serious issue of excessive CO2 emission and energy crisis.

15.
Biomark Med ; 17(10): 497-507, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37526144

RESUMO

Background: The impact of lymphocyte-C-reactive protein ratio (LCR) on clinical outcomes has been reported in liver cancer such as hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC), but the results remain inconsistent. Methods: We searched PubMed, Scopus, Web of Science, Embase and Cochrane Library databases for relevant studies evaluating the association of LCR with survival outcomes and clinicopathological parameters. Results: Eight studies with 4316 patients were included in this meta-analysis. Low LCR was significantly associated with poor overall survival, disease-free survival/relapse-free survival and disease progression clinicopathological parameters in patients with HCC or ICC. Conclusion: Low pretreatment LCR was an adverse prognostic indicator in patients with HCC or ICC. In addition, it was correlated with clinicopathological parameters indicating a higher stage of malignancy.


Assuntos
Neoplasias dos Ductos Biliares , Carcinoma Hepatocelular , Colangiocarcinoma , Neoplasias Hepáticas , Humanos , Neoplasias Hepáticas/patologia , Carcinoma Hepatocelular/patologia , Prognóstico , Proteína C-Reativa , Colangiocarcinoma/diagnóstico , Ductos Biliares Intra-Hepáticos/patologia , Linfócitos/patologia
16.
EMBO Rep ; 24(8): e56297, 2023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37306041

RESUMO

Precise regulation of mitochondrial fusion and fission is essential for cellular activity and animal development. Imbalances between these processes can lead to fragmentation and loss of normal membrane potential in individual mitochondria. In this study, we show that MIRO-1 is stochastically elevated in individual fragmented mitochondria and is required for maintaining mitochondrial membrane potential. We further observe a higher level of membrane potential in fragmented mitochondria in fzo-1 mutants and wounded animals. Moreover, MIRO-1 interacts with VDAC-1, a crucial mitochondrial ion channel located in the outer mitochondrial membrane, and this interaction depends on the residues E473 of MIRO-1 and K163 of VDAC-1. The E473G point mutation disrupts their interaction, resulting in a reduction of the mitochondrial membrane potential. Our findings suggest that MIRO-1 regulates membrane potential and maintains mitochondrial activity and animal health by interacting with VDAC-1. This study provides insight into the mechanisms underlying the stochastic maintenance of membrane potential in fragmented mitochondria.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Potencial da Membrana Mitocondrial , Mitocôndrias/genética , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Canal de Ânion 1 Dependente de Voltagem/genética , Canal de Ânion 1 Dependente de Voltagem/metabolismo
17.
Org Lett ; 25(24): 4525-4529, 2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37288936

RESUMO

An oxidative azido-difluoromethylthiolation of alkenes by employing TMSN3 as the azide source and PhSO2SCF2H as the difluoromethylthiolation reagent is reported. The present method is characterized by good functional group tolerance, broad substrate scope, and short reaction time, thereby providing an efficient access to synthetically useful ß-difluoromethylthiolated azides. Mechanistic studies indicate a radical pathway involved in the reaction.


Assuntos
Alcenos , Azidas , Alcenos/química , Azidas/química , Catálise , Indicadores e Reagentes
18.
Nat Struct Mol Biol ; 30(6): 785-799, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37188808

RESUMO

Mitochondrial antiviral signaling protein (MAVS) is an adapter that recruits and activates IRF3. However, the mechanisms underpinning the interplay between MAVS and IRF3 are largely unknown. Here we show that small ubiquitin-like modifier (SUMO)-specific protease 1 negatively regulates antiviral immunity by deSUMOylating MAVS. Upon virus infection, PIAS3-induced poly-SUMOylation promotes lysine 63-linked poly-ubiquitination and aggregation of MAVS. Notably, we observe that SUMO conjugation is required for MAVS to efficiently produce phase-separated droplets through association with a newly identified SUMO-interacting motif (SIM) in MAVS. We further identify a yet-unknown SIM in IRF3 that mediates its enrichment to the multivalent MAVS droplets. Conversely, IRF3 phosphorylation at crucial residues close to SIM rapidly disables SUMO-SIM interactions and releases activated IRF3 from MAVS. Our findings implicate SUMOylation in MAVS phase separation and suggest a thus far unknown regulatory process by which IRF3 can be efficiently recruited and released to facilitate timely activation of antiviral responses.


Assuntos
Sumoilação , Ubiquitina , Ubiquitinação , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Antivirais
19.
Nutr Cancer ; 75(4): 1233-1242, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36895192

RESUMO

Previous studies have investigated the prognostic value of the advanced lung cancer inflammation index (ALI) in gastrointestinal (GI) cancers; however, the results are controversial. This meta-analysis aimed to evaluate the prognostic and clinicopathological role of ALI in patients with GI cancers. A systematic search of electronic databases was conducted to evaluate the prognostic and clinicopathological value of ALI in GI cancers. Nine studies comprising 3,750 patients were included in this meta-analysis. The pooled results showed that a low ALI was significantly associated with worse overall survival (OS, hazard ratio [HR] = 1.95, 95% confidence interval [CI] = 1.53-2.47, P < 0.001, I2 = 63.9%) and disease-free survival/relapse-free survival (DFS/RFS, HR = 1.49, 95% CI = 1.28-1.73, P < 0.001, I2 = 0%) in patients with GI cancers. In addition, decreased ALI correlated with the depth of tumor invasion and presence of distant metastasis and tended to be associated with male sex, high carcinoembryonic antigen levels, lymph node metastasis, and right-sided colon cancer. Low ALI was associated with adverse OS and DFS/RFS in patients with GI cancer. In addition, decreased ALI also correlated with clinicopathological factors, indicating higher stage of the malignancy.


Assuntos
Neoplasias Gastrointestinais , Neoplasias Pulmonares , Humanos , Masculino , Prognóstico , Neoplasias Gastrointestinais/complicações , Neoplasias Gastrointestinais/patologia , Modelos de Riscos Proporcionais , Inflamação
20.
Redox Biol ; 61: 102642, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36863169

RESUMO

Identifying direct substrates of enzymes has been a long-term challenge. Here, we present a strategy using live cell chemical cross-linking and mass spectrometry to identify the putative substrates of enzymes for further biochemical validation. Compared with other methods, our strategy is based on the identification of cross-linked peptides supported by high-quality MS/MS spectra, which eliminates false-positive discoveries of indirect binders. Additionally, cross-linking sites allow the analysis of interaction interfaces, providing further information for substrate validation. We demonstrated this strategy by identifying direct substrates of thioredoxin in both E. coli and HEK293T cells using two bis-vinyl sulfone chemical cross-linkers BVSB and PDES. We confirmed that BVSB and PDES have high specificity in cross-linking the active site of thioredoxin with its substrates both in vitro and in live cells. Applying live cell cross-linking, we identified 212 putative substrates of thioredoxin in E. coli and 299 putative S-nitrosylation (SNO) substrates of thioredoxin in HEK293T cells. In addition to thioredoxin, we have shown that this strategy can be applied to other proteins in the thioredoxin superfamily. Based on these results, we believe future development of cross-linking techniques will further advance cross-linking mass spectrometry in identifying substrates of other classes of enzymes.


Assuntos
Oxirredutases , Mapeamento de Interação de Proteínas , Espectrometria de Massas em Tandem , Humanos , Escherichia coli/metabolismo , Células HEK293 , Oxirredutases/metabolismo , Espectrometria de Massas em Tandem/métodos , Tiorredoxinas/metabolismo , Mapeamento de Interação de Proteínas/métodos
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