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1.
PLoS One ; 19(5): e0302692, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38722893

RESUMO

Tobacco vein necrosis (TVN) is a complex phenomenon regulated by different genetic determinants mapped in the HC-Pro protein (amino acids N330, K391 and E410) and in two regions of potato virus Y (PVY) genome, corresponding to the cytoplasmic inclusion (CI) protein and the nuclear inclusion protein a-protease (NIa-Pro), respectively. A new determinant of TVN was discovered in the MK isolate of PVY which, although carried the HC-Pro determinants associated to TVN, did not induce TVN. The HC-Pro open reading frame (ORF) of the necrotic infectious clone PVY N605 was replaced with that of the non-necrotic MK isolate, which differed only by one amino acid at position 392 (T392 instead of I392). The cDNA clone N605_MKHCPro inoculated in tobacco induced only weak mosaics at the systemic level, demostrating that the amino acid at position 392 is a new determinant for TVN. No significant difference in accumulation in tobacco was observed between N605 and N605_MKHCPro. Since phylogenetic analyses showed that the loss of necrosis in tobacco has occurred several times independently during PVY evolution, these repeated evolutions strongly suggest that tobacco necrosis is a costly trait in PVY.


Assuntos
Nicotiana , Filogenia , Doenças das Plantas , Mutação Puntual , Potyvirus , Proteínas Virais , Nicotiana/virologia , Potyvirus/genética , Potyvirus/patogenicidade , Doenças das Plantas/virologia , Proteínas Virais/genética , Proteínas Virais/metabolismo , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Sequência de Aminoácidos , Necrose , Dados de Sequência Molecular , Fases de Leitura Aberta/genética
2.
Biomacromolecules ; 25(5): 2762-2769, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38689446

RESUMO

Protein-based encapsulin nanocompartments, known for their well-defined structures and versatile functionalities, present promising opportunities in the fields of biotechnology and nanomedicine. In this investigation, we effectively developed a sortase A-mediated protein ligation system in Escherichia coli to site-specifically attach target proteins to encapsulin, both internally and on its surfaces without any further in vitro steps. We explored the potential applications of fusing sortase enzyme and a protease for post-translational ligation of encapsulin to a green fluorescent protein and anti-CD3 scFv. Our results demonstrated that this system could attach other proteins to the nanoparticles' exterior surfaces without adversely affecting their folding and assembly processes. Additionally, this system enabled the attachment of proteins inside encapsulins which varied shapes and sizes of the nanoparticles due to cargo overload. This research developed an alternative enzymatic ligation method for engineering encapsulin nanoparticles to facilitate the conjugation process.


Assuntos
Aminoaciltransferases , Proteínas de Bactérias , Cisteína Endopeptidases , Escherichia coli , Processamento de Proteína Pós-Traducional , Aminoaciltransferases/metabolismo , Aminoaciltransferases/química , Cisteína Endopeptidases/metabolismo , Cisteína Endopeptidases/química , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Escherichia coli/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Fluorescência Verde/química , Nanopartículas/química , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/metabolismo
3.
Toxins (Basel) ; 16(4)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38668619

RESUMO

Cholera toxoid is an established tool for use in cellular tracing in neuroscience and cell biology. We use a sortase labeling approach to generate site-specific N-terminally modified variants of both the A2-B5 heterohexamer and B5 pentamer forms of the toxoid. Both forms of the toxoid are endocytosed by GM1-positive mammalian cells, and while the heterohexameric toxoid was principally localized in the ER, the B5 pentamer showed an unexpectedly specific localization in the medial/trans-Golgi. This study suggests a future role for specifically labeled cholera toxoids in live-cell imaging beyond their current applications in neuronal tracing and labeling of lipid rafts in fixed cells.


Assuntos
Toxina da Cólera , Cisteína Endopeptidases , Complexo de Golgi , Humanos , Toxina da Cólera/metabolismo , Cisteína Endopeptidases/metabolismo , Complexo de Golgi/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Aminoaciltransferases/metabolismo , Aminoaciltransferases/genética , Endocitose
4.
Int J Mol Sci ; 25(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38673995

RESUMO

In recent decades, neglected tropical diseases and poverty-related diseases have become a serious health problem worldwide. Among these pathologies, human African trypanosomiasis, and malaria present therapeutic problems due to the onset of resistance, toxicity problems and the limited spectrum of action. In this drug discovery process, rhodesain and falcipain-2, of Trypanosoma brucei rhodesiense and Plasmodium falciparum, are currently considered the most promising targets for the development of novel antitrypanosomal and antiplasmodial agents, respectively. Therefore, in our study we identified a novel lead-like compound, i.e., inhibitor 2b, which we proved to be active against both targets, with a Ki = 5.06 µM towards rhodesain and an IC50 = 40.43 µM against falcipain-2.


Assuntos
Inibidores de Cisteína Proteinase , Nitrilas , Plasmodium falciparum , Trypanosoma brucei rhodesiense , Tripanossomíase Africana , Humanos , Antimaláricos/uso terapêutico , Antimaláricos/farmacologia , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Inibidores de Cisteína Proteinase/uso terapêutico , Inibidores de Cisteína Proteinase/química , Malária/tratamento farmacológico , Nitrilas/uso terapêutico , Plasmodium falciparum/efeitos dos fármacos , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/metabolismo , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêutico , Trypanosoma brucei rhodesiense/efeitos dos fármacos , Tripanossomíase Africana/tratamento farmacológico
5.
Bioconjug Chem ; 35(5): 665-673, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38598424

RESUMO

Enhancing the accumulation and retention of small-molecule probes in tumors is an important way to achieve accurate cancer diagnosis and therapy. Enzyme-stimulated macrocyclization of small molecules possesses great potential for enhanced positron emission tomography (PET) imaging of tumors. Herein, we reported an 18F-labeled radiotracer [18F]AlF-RSM for legumain detection in vivo. The tracer was prepared by a one-step aluminum-fluoride-restrained complexing agent ([18F]AlF-RESCA) method with high radiochemical yield (RCY) (88.35 ± 3.93%) and radiochemical purity (RCP) (>95%). More notably, the tracer can be transformed into a hydrophobic macrocyclic molecule under the joint action of legumain and reductant. Simultaneously, the tracer could target legumain-positive tumors and enhance accumulation and retention in tumors, resulting in the amplification of PET imaging signals. The enhancement of radioactivity enables PET imaging of legumain activity with high specificity. We envision that, by combining this highly efficient 18F-labeled strategy with our intramolecular macrocyclization reaction, a range of radiofluorinated tracers can be designed for tumor PET imaging and early cancer diagnosis in the future.


Assuntos
Cisteína Endopeptidases , Radioisótopos de Flúor , Tomografia por Emissão de Pósitrons , Tomografia por Emissão de Pósitrons/métodos , Radioisótopos de Flúor/química , Cisteína Endopeptidases/metabolismo , Cisteína Endopeptidases/análise , Animais , Ciclização , Camundongos , Humanos , Compostos Radiofarmacêuticos/química , Linhagem Celular Tumoral , Camundongos Endogâmicos BALB C , Fluoretos/química , Camundongos Nus
6.
Oncogene ; 43(21): 1581-1593, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38565942

RESUMO

Deubiquitinating enzymes (DUBs) are promising targets for cancer therapy because of their pivotal roles in various physiological and pathological processes. Among these, ubiquitin-specific peptidase 26 (USP26) is a protease with crucial regulatory functions. Our study sheds light on the upregulation of USP26 in colorectal cancer (CRC), in which its increased expression correlates with an unfavorable prognosis. Herein, we evidenced the role of USP26 in promoting CRC tumorigenesis in a parkin RBR E3 ubiquitin-protein ligase (PRKN) protein-dependent manner. Our investigation revealed that USP26 directly interacted with PRKN protein, facilitating its deubiquitination, and subsequently reducing its activity. Additionally, we identified the K129 site on PRKN as a specific target for USP26-mediated deubiquitination. Our research highlights that a K-to-R mutation at the site on PRKN diminishes its potential for activation and ability to mediate mitophagy. In summary, our findings underscore the significance of USP26-mediated deubiquitination in restraining the activation of the PRKN-mediated mitophagy pathway, ultimately driving CRC tumorigenesis. This study not only elucidated the multifaceted role of USP26 in CRC but also introduced a promising avenue for therapeutic exploration through the development of small molecule inhibitors targeting USP26. This strategy holds promise as a novel therapeutic approach for CRC.


Assuntos
Carcinogênese , Neoplasias Colorretais , Mitofagia , Ubiquitina-Proteína Ligases , Ubiquitinação , Neoplasias Colorretais/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Humanos , Mitofagia/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Animais , Carcinogênese/genética , Carcinogênese/metabolismo , Camundongos , Linhagem Celular Tumoral , Cisteína Endopeptidases/metabolismo , Cisteína Endopeptidases/genética , Camundongos Nus , Regulação Neoplásica da Expressão Gênica
7.
J Cell Sci ; 137(10)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38682259

RESUMO

SARS-CoV-2 interferes with antigen presentation by downregulating major histocompatibility complex (MHC) II on antigen-presenting cells, but the mechanism mediating this process is unelucidated. Herein, analysis of protein and gene expression in human antigen-presenting cells reveals that MHC II is downregulated by the SARS-CoV-2 main protease, NSP5. This suppression of MHC II expression occurs via decreased expression of the MHC II regulatory protein CIITA. CIITA downregulation is independent of the proteolytic activity of NSP5, and rather, NSP5 delivers HDAC2 to the transcription factor IRF3 at an IRF-binding site within the CIITA promoter. Here, HDAC2 deacetylates and inactivates the CIITA promoter. This loss of CIITA expression prevents further expression of MHC II, with this suppression alleviated by ectopic expression of CIITA or knockdown of HDAC2. These results identify a mechanism by which SARS-CoV-2 limits MHC II expression, thereby delaying or weakening the subsequent adaptive immune response.


Assuntos
Antígenos de Histocompatibilidade Classe II , Histona Desacetilase 2 , Proteínas Nucleares , Regiões Promotoras Genéticas , SARS-CoV-2 , Transativadores , Humanos , Histona Desacetilase 2/metabolismo , Histona Desacetilase 2/genética , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , SARS-CoV-2/imunologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Antígenos de Histocompatibilidade Classe II/genética , Transativadores/metabolismo , Transativadores/genética , Regiões Promotoras Genéticas/genética , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , COVID-19/virologia , COVID-19/imunologia , COVID-19/genética , COVID-19/metabolismo , Fator Regulador 3 de Interferon/metabolismo , Fator Regulador 3 de Interferon/genética , Proteínas não Estruturais Virais/metabolismo , Proteínas não Estruturais Virais/genética , Células Apresentadoras de Antígenos/metabolismo , Células Apresentadoras de Antígenos/imunologia , Células HEK293 , Regulação para Baixo/genética , Apresentação de Antígeno/genética , Cisteína Endopeptidases/metabolismo , Cisteína Endopeptidases/genética
8.
J Microbiol Methods ; 221: 106928, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38583783

RESUMO

The bicistronic expression system that utilizes fluorescent reporters has been demonstrated to be a straightforward method for detecting recombinant protein expression levels, particularly when compared to polyacrylamide gel electrophoresis and immunoblot analysis, which are tedious and labor-intensive. However, existing bicistronic reporter systems are less capable of quantitative measurement due to the lag in reporter expression and its negative impact on target protein. In this work, a plug and play bicistronic construct using mCherry as reporter was applied in the screening of optimal replicon and promoter for Sortase expression in Escherichia coli (E. coli). The bicistronic construct allowed the reporter gene and target open reading frame (ORF) to be co-transcribed under the same promoter, resulting in a highly positive quantitative correlation between the expression titer of Sortase and the fluorescent intensity (R2 > 0.97). With the correlation model, the titer of target protein can be quantified by noninvasively measuring the fluorescent intensity. On top of this, the expression of reporter has no significant effect on the yield of target protein, thus favoring a plug and play design for removing reporter gene to generate a plain plasmid for industrial use.


Assuntos
Escherichia coli , Genes Reporter , Proteínas Luminescentes , Plasmídeos , Regiões Promotoras Genéticas , Proteínas Recombinantes , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Luminescentes/genética , Plasmídeos/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteína Vermelha Fluorescente , Fases de Leitura Aberta , Expressão Gênica , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Vetores Genéticos , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Regulação Bacteriana da Expressão Gênica , Replicon/genética
9.
Virus Res ; 344: 199369, 2024 06.
Artigo em Inglês | MEDLINE | ID: mdl-38608732

RESUMO

Tobacco (Nicotiana tabacum) is one of the major cash crops in China. Potato virus Y (PVY), a representative member of the genus Potyvirus, greatly reduces the quality and yield of tobacco leaves by inducing veinal necrosis. Mild strain-mediated cross-protection is an attractive method of controlling diseases caused by PVY. Currently, there is a lack of effective and stable attenuated PVY mutants. Potyviral helper component-protease (HC-Pro) is a likely target for the development of mild strains. Our previous studies showed that the residues lysine at positions 124 and 182 (K124 and K182) in HC-Pro were involved in PVY virulence, and the conserved KITC motif in HC-Pro was involved in aphid transmission. In this study, to improve the stability of PVY mild strains, K at position 50 (K50) in KITC motif, K124, and K182 were separately substituted with glutamic acid (E), leucine (L), and arginine (R), resulting in a triple-mutant PVY-HCELR. The mutant PVY-HCELR had attenuated virulence and did not induce leaf veinal necrosis symptoms in tobacco plants and could not be transmitted by Myzus persicae. Furthermore, PVY-HCELR mutant was genetically stable after six serial passages, and only caused mild mosaic symptoms in tobacco plants even at 90 days post inoculation. The tobacco plants cross-protected by PVY-HCELR mutant showed high resistance to the wild-type PVY. This study showed that PVY-HCELR mutant was a promising mild mutant for cross-protection to control PVY.


Assuntos
Proteção Cruzada , Mutação , Nicotiana , Doenças das Plantas , Potyvirus , Proteínas Virais , Potyvirus/genética , Potyvirus/patogenicidade , Potyvirus/enzimologia , Nicotiana/virologia , Doenças das Plantas/virologia , Proteínas Virais/genética , Proteínas Virais/metabolismo , Virulência , Animais , Afídeos/virologia , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Folhas de Planta/virologia , China
10.
Virology ; 595: 110070, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38657363

RESUMO

Foot-and-mouth disease is a highly contagious and infectious disease affecting cloven-hoofed animals. Disease control is complicated by its highly contagious nature and antigenic diversity. Host microRNAs (miRNAs) are post-transcriptional regulators that either promote or repress viral replications in virus infection. In the present study, we found that ssc-miR-7139-3p (Sus scrofa miR-7139-3p) was significantly up-regulated in host cells during foot-and-mouth disease virus (FMDV) infection. Overexpression of miR-7139-3p attenuated FMDV replication, whereas inhibition promoted FMDV replication. In addition, the survival rate of FMDV infected suckling mice was increased through injection of miR-7139-3p agomiR. Further studies revealed that miR-7139-3p targets Bcl-2 to initiate the apoptotic pathway and caspase-3 cleaved 3Cpro behind the 174th aspartic acid (D174), which eventually promotes the degradation of 3Cpro. Overall, our findings demonstrate that miR-7139-3p suppresses FMDV replication by promoting degradation of 3Cpro through targeting the apoptosis-negative regulatory gene Bcl-2.


Assuntos
Apoptose , Vírus da Febre Aftosa , Febre Aftosa , MicroRNAs , Proteínas Proto-Oncogênicas c-bcl-2 , Replicação Viral , Animais , Vírus da Febre Aftosa/genética , Vírus da Febre Aftosa/fisiologia , MicroRNAs/genética , MicroRNAs/metabolismo , Febre Aftosa/virologia , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Suínos , Proteínas Virais/genética , Proteínas Virais/metabolismo , Proteases Virais 3C/metabolismo , Linhagem Celular , Sus scrofa , Interações Hospedeiro-Patógeno , Cisteína Endopeptidases/metabolismo , Cisteína Endopeptidases/genética , Proteólise , Caspase 3/metabolismo , Caspase 3/genética
11.
Int J Biol Macromol ; 265(Pt 1): 130644, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38462102

RESUMO

The main proteinase (Mpro) of SARS-CoV-2 plays a critical role in cleaving viral polyproteins into functional proteins required for viral replication and assembly, making it a prime drug target for COVID-19. It is well known that noncompetitive inhibition offers potential therapeutic options for treating COVID-19, which can effectively reduce the likelihood of cross-reactivity with other proteins and increase the selectivity of the drug. Therefore, the discovery of allosteric sites of Mpro has both scientific and practical significance. In this study, we explored the binding characteristics and inhibiting process of Mpro activity by two recently reported allosteric inhibitors, pelitinib and AT7519 which were obtained by the X-ray screening experiments, to probe the allosteric mechanism via molecular dynamic (MD) simulations. We found that pelitinib and AT7519 can stably bind to Mpro far from the active site. The binding affinity is estimated to be -24.37 ± 4.14 and - 26.96 ± 4.05 kcal/mol for pelitinib and AT7519, respectively, which is considerably stable compared with orthosteric drugs. Furthermore, the strong binding caused clear changes in the catalytic site of Mpro, thus decreasing the substrate accessibility. The community network analysis also validated that pelitinib and AT7519 strengthened intra- and inter-domain communication of Mpro dimer, resulting in a rigid Mpro, which could negatively impact substrate binding. In summary, our findings provide the detailed working mechanism for the two experimentally observed allosteric sites of Mpro. These allosteric sites greatly enhance the 'druggability' of Mpro and represent attractive targets for the development of new Mpro inhibitors.


Assuntos
Aminoquinolinas , Compostos de Anilina , COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/metabolismo , Peptídeo Hidrolases/metabolismo , Inibidores de Proteases/química , Simulação de Acoplamento Molecular , Cisteína Endopeptidases/metabolismo , Simulação de Dinâmica Molecular , Antivirais/farmacologia , Antivirais/química
12.
Biochim Biophys Acta Mol Basis Dis ; 1870(4): 167104, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38437993

RESUMO

Ischemic stroke is the main cause of death and disability, and microglia play a crucial role in the pathophysiology of hypoxic ischemic brain injury. We found that SENP3 is highly expressed in the early stages of ischemic stroke in both in vivo and in vitro mouse models, and may be related to the deSUMOylation of the key kinase MKK7 in the TLR4/p-JNK signaling pathway. Knocking down SENP3 can inhibit the deSUMOylation of MKK7, thereby inhibiting the activation of the TLR4/p-JNK signaling pathway in an in vitro stroke model. Proteomic analysis showed that SENP3 undergoes phosphorylation at the T429 site after ischemic stroke. Computer simulation predictions show a significant enhancement of the interaction between pT429-SENP3 and MKK7, which has been confirmed through experiments on the interaction of biological macromolecules (SPR). The mitochondrial metabolic abnormalities caused by energy abnormalities in the early stages of stroke provide a good explanation for the phosphorylation of SENP3. Therefore, we used the mitochondrial complex inhibitor TTFA to reverse demonstrate that the phosphorylation of SENP3 comes from the large amount of adenosine triphosphate produced by mitochondrial abnormal metabolism caused by early oxygen glucose deficiency. Finally, proteomic analysis indicates that a significant amount of oxidative phosphorylation does occur in the early stages of stroke. In summary, targeted regulation of SENP3 phosphorylation to affect the deSUMOylation of MKK7 may inhibit secondary inflammation in ischemic stroke.


Assuntos
AVC Isquêmico , Camundongos , Animais , Simulação por Computador , Proteômica , Receptor 4 Toll-Like , Cisteína Endopeptidases/metabolismo , Inflamação/metabolismo
13.
Antiviral Res ; 225: 105874, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38555023

RESUMO

The main protease (MPro) of SARS-CoV-2, the causative agent of COVID-19, is a pivotal nonstructural protein critical for viral replication and pathogenesis. Its protease function relies on three active site pockets for substrate recognition and a catalytic cysteine for enzymatic activity. To develop potential SARS-CoV-2 antivirals, we successfully synthesized a diverse range of azapeptide inhibitors with various covalent warheads to target MPro's catalytic cysteine. Our characterization identified potent MPro inhibitors, including MPI89 that features an aza-2,2-dichloroacetyl warhead with a remarkable EC50 value of 10 nM against SARS-CoV-2 infection in ACE2+ A549 cells and a selective index of 875. MPI89 is also remarkably selective and shows no potency against SARS-CoV-2 papain-like protease and several human proteases. Crystallography analyses demonstrated that these inhibitors covalently engaged the catalytic cysteine and used the aza-amide carbonyl oxygen to bind to the oxyanion hole. MPI89 stands as one of the most potent MPro inhibitors, suggesting the potential for further exploration of azapeptides and the aza-2,2-dichloroacetyl warhead for developing effective therapeutics against COVID-19.


Assuntos
COVID-19 , Proteases 3C de Coronavírus , SARS-CoV-2 , Humanos , SARS-CoV-2/metabolismo , Cisteína , Cisteína Endopeptidases/metabolismo , Proteínas não Estruturais Virais , Inibidores de Proteases/farmacologia , Antivirais/farmacologia
14.
J Theor Biol ; 582: 111757, 2024 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-38336240

RESUMO

BACKGROUND: Factor X activation by the phospholipid-bound intrinsic tenase complex is a critical membrane-dependent reaction of blood coagulation. Its regulation mechanisms are unclear, and a number of questions regarding diffusional limitation, pathways of assembly and substrate delivery remain open. METHODS: We develop and analyze here a detailed mechanism-driven computer model of intrinsic tenase on phospholipid surfaces. Three-dimensional reaction-diffusion-advection and stochastic simulations were used where appropriate. RESULTS: Dynamics of the system was predominantly non-stationary under physiological conditions. In order to describe experimental data, we had to assume both membrane-dependent and solution-dependent delivery of the substrate. The former pathway dominated at low cofactor concentration, while the latter became important at low phospholipid concentration. Factor VIIIa-factor X complex formation was the major pathway of the complex assembly, and the model predicted high affinity for their lipid-dependent interaction. Although the model predicted formation of the diffusion-limited layer of substrate for some conditions, the effects of this limitation on the fXa production were small. Flow accelerated fXa production in a flow reactor model by bringing in fIXa and fVIIIa rather than fX. CONCLUSIONS: This analysis suggests a concept of intrinsic tenase that is non-stationary, employs several pathways of substrate delivery depending on the conditions, and is not particularly limited by diffusion of the substrate.


Assuntos
Fator X , Proteínas de Neoplasias , Fosfolipídeos , Fator X/metabolismo , Fosfolipídeos/metabolismo , Fator IXa/metabolismo , Cisteína Endopeptidases/metabolismo , Cinética
15.
Protein Expr Purif ; 218: 106458, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38423156

RESUMO

Trypanosoma cruzi is the causative agent of Chagas disease, a global public health problem. New therapeutic drugs and biologics are needed. The TSA-1 recombinant protein of T. cruzi is one such promising antigen for developing a therapeutic vaccine. However, it is overexpressed in E. coli as inclusion bodies, requiring an additional refolding step. As an alternative, in this study, we propose the endogenous cysteine protease inhibitor chagasin as a molecular scaffold to generate chimeric proteins. These proteins will contain combinations of two of the five conserved epitopes (E1 to E5) of TSA-1 in the L4 and L6 chagasin loops. Twenty chimeras (Q1-Q20) were designed, and their solubility was predicted using bioinformatics tools. Nine chimeras with different degrees of solubility were selected and expressed in E. coli BL21 (DE3). Western blot assays with anti-6x-His and anti-chagasin antibodies confirmed the expression of soluble recombinant chimeras. Both theoretically and experimentally, the Q12 (E5-E3) chimera was the most soluble, and the Q20 (E4-E5) the most insoluble protein. Q4 (E5-E1) and Q8 (E5-E2) chimeras were classified as proteins with medium solubility that exhibited the highest yield in the soluble fraction. Notably, Q4 has a yield of 239 mg/L, well above the yield of recombinant chagasin (16.5 mg/L) expressed in a soluble form. The expression of the Q4 chimera was scaled up to a 7 L fermenter obtaining a yield of 490 mg/L. These data show that chagasin can serve as a molecular scaffold for the expression of TSA-1 epitopes in the form of soluble chimeras.


Assuntos
Proteínas de Membrana , Trypanosoma cruzi , Trypanosoma cruzi/genética , Cisteína Endopeptidases/metabolismo , Epitopos/genética , Epitopos/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo
16.
Brief Bioinform ; 25(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38305454

RESUMO

This opinion article addresses a major issue in molecular biology and drug discovery by highlighting the complications that arise from combining polyproteins and their functional products within the same database entry. This problem, exemplified by the discovery of novel inhibitors for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease, has an influence on our ability to retrieve precise data and hinders the development of targeted therapies. It also emphasizes the need for improved database practices and underscores their significance in advancing scientific research. Furthermore, it emphasizes the need of learning from the SARS-CoV-2 pandemic in order to improve global preparedness for future health crises.


Assuntos
COVID-19 , Humanos , Poliproteínas/metabolismo , Cisteína Endopeptidases/metabolismo , SARS-CoV-2/metabolismo , Descoberta de Drogas , Simulação de Acoplamento Molecular
17.
Discov Med ; 36(181): 355-365, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38409840

RESUMO

BACKGROUND: Arg-gingipain A (rgpA) and Arg-gingipain B (rgpB) are crucial virulence factors associated with Porphyromonas gingivalis (P. gingivalis) and have been recognized as promising targets for antibacterial vaccines. Although vaccines containing rgpA have shown efficacy, the incorporation of rgpB, which lacks the haemagglutinin adhesin (HA) domain, diminishes the vaccine's effectiveness. This study aims to assess the immunogenicity of the functional HA domain of rgpA in mouse periodontitis models. METHODS: A total of 24 mice were randomly divided into four groups, each receiving different immune injections: group A received phosphate-buffered saline (PBS) as an empty control; group B received pVAX1 as a negative control (NC); group C received pVAX1-HA; and group D received pVAX1-rgpA. The mice were subjected to intramuscular injections every two weeks for a total of three administrations. Prior to each immunization, blood samples were collected for antibody detection under isoflurane anesthesia. Following the final immunization, periodontitis was induced two weeks later by using sutures soaked in a P. gingivalis solution. The mice were euthanized after an additional two-week period. To assess the safety of the procedure, major organs were examined through hematoxylin-eosin (HE) staining. Subsequently, the levels of IgG, IgG1, and IgG2a in the serum were quantified via enzyme-linked immunosorbent assay (ELISA). Additionally, the expression of inflammatory factors in the gingiva, including interleukin-6 (IL-6), interleukin-1ß (IL-1ß), and tumor necrosis factor alpha (TNF-α), was determined using quantitative real-time reverse transcript PCR (qRT-PCR). The extent of bone loss in periodontal tissues was evaluated using micro-computed tomography (micro-CT) and HE staining. RESULTS: HE staining of the organs confirmed the absence of vaccine-induced toxicity in vivo. After the second immunization, both the rgpA and HA groups displayed significantly higher specific IgG titers in comparison to the NC and PBS groups (p < 0.05). Furthermore, the rgpA and HA groups exhibited a noteworthy predominance of IgG1 antibodies after three immunization doses, while there was a noticeable reduction in IgG2a levels observed following ligation with P. gingivalis sutures, as opposed to the NC and PBS groups (p < 0.05). Additionally, both the HA and rgpA groups showed a significant decrease in the expression of inflammatory factors such as IL-6, IL-1ß, and TNF-α, as well as a reduction in bone loss around periodontitis-affected teeth, when compared to the NC and PBS groups (p < 0.05). CONCLUSIONS: The results of this study demonstrate that the rgpA-engineered/functionalized HA gene vaccine is capable of eliciting a potent prophylactic immune response against P. gingivalis-induced periodontitis, effectively serving as an immunogenic and protective agent in vivo.


Assuntos
Periodontite , Vacinas de DNA , Camundongos , Animais , Cisteína Endopeptidases Gingipaínas , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Vacinas de DNA/uso terapêutico , Porphyromonas gingivalis/genética , Interleucina-6 , Fator de Necrose Tumoral alfa , Microtomografia por Raio-X , Adesinas Bacterianas , Vacinação , Periodontite/prevenção & controle , Imunoglobulina G
18.
Funct Integr Genomics ; 24(2): 40, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38383667

RESUMO

As a common malignant tumor, esophageal squamous cell carcinoma (ESCC) is occasionally seen in clinical practice. This type of disease has low incidence rate and mortality. The post-translational modification of small ubiquitin like modifiers (SUMO) can play a crucial role in regulating protein function, and can significantly impact the occurrence and development of diseases. SUMO-specific peptidase (SENP) affects cell activity by regulating the biological function of SUMO. SENP3 belongs to the SENP family, and available data indicate that many malignancies are associated with SENPs, it is currently unclear its role in ESCC. This study indicates that there is a high level of SENP3 expression in ESCC tumor cells. If the expression level of this gene is high, it can have a significant impact on ESCC cell lines and affect physiological activities such as invasion of KYSE170 cells. If the gene is knocked out, this situation will not occur. There is also research data indicating that this gene can effectively activate related signaling pathways, thereby promoting the physiological activities of malignant tumor cells. In a nude mouse xenograft tumor model, KYSE170 cells with SENP3 expression knockdown induced a smaller volume and weight of tumor tissue. Therefore, it can be clearly stated that SENP3 can enable Wnt/ ß- The catenin signaling pathway is stimulated, which in turn affects the physiological activities of ESCC cells, including the invasion process. The results of this article lay the foundation for clinical staff to carry out clinical management.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Animais , Humanos , Camundongos , Carcinoma de Células Escamosas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/metabolismo , Carcinoma de Células Escamosas do Esôfago/patologia , Regulação Neoplásica da Expressão Gênica , Via de Sinalização Wnt/genética
19.
Chem Biodivers ; 21(5): e202301659, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38407541

RESUMO

Sortase A (SrtA) is an attractive target for developing new anti-infective drugs that aim to interfere with essential virulence mechanisms, such as adhesion to host cells and biofilm formation. Herein, twenty hydroxy, nitro, bromo, fluoro, and methoxy substituted chalcone compounds were synthesized, antimicrobial activities and molecular modeling strategies against the SrtA enzyme were investigated. The most active compounds were found to be T2, T4, and T19 against Streptococcus mutans (S. mutans) with MIC values of 1.93, 3.8, 3.94 µg/mL, and docking scores of -6.46, -6.63, -6.73 kcal/mol, respectively. Also, these three active compounds showed better activity than the chlorohexidine (CHX) (MIC value: 4.88 µg/mL, docking score: -6.29 kcal/mol) in both in vitro and in silico. Structural stability and binding free energy analysis of S.mutans SrtA with active compounds were measured by molecular dynamic (MD) simulations throughout 100 nanoseconds (ns) time. It was observed that the stability of the critical interactions between these compounds and the target enzyme was preserved. To prove further, in vivo biological evaluation studies could be conducted for the most promising precursor compounds T2, T4, and T19, and it might open new avenues to the discovery of more potent SrtA inhibitors.


Assuntos
Aminoaciltransferases , Proteínas de Bactérias , Cisteína Endopeptidases , Testes de Sensibilidade Microbiana , Streptococcus mutans , Aminoaciltransferases/antagonistas & inibidores , Aminoaciltransferases/metabolismo , Cisteína Endopeptidases/metabolismo , Cisteína Endopeptidases/química , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/enzimologia , Antibacterianos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Relação Estrutura-Atividade , Simulação de Dinâmica Molecular , Simulação de Acoplamento Molecular , Estrutura Molecular , Modelos Moleculares , Chalcona/química , Chalcona/farmacologia , Chalcona/síntese química , Relação Dose-Resposta a Droga
20.
Oncogene ; 43(14): 1050-1062, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38374407

RESUMO

In a previous study, we discovered that the level of lnc-TSPAN12 was significantly elevated in hepatocellular carcinoma (HCC) and correlated with a low survival rate. However, the function and mechanism of lnc-TSPAN12 in modulating epithelial-mesenchymal transition (EMT) and metastasis in HCC remains poorly understood. This study demonstrates that lnc-TSPAN12 positively influences migration, invasion, and EMT of HCC cells in vitro and promotes hepatic metastasis in vivo. The modification of N6-methyladenosine, driven by METTL3, is essential for the stability of lnc-TSPAN12, which may partially contribute to the upregulation of lnc-TSPAN12. Mechanistically, lnc-TSPAN12 exhibits direct interactions with EIF3I and SENP1, acting as a scaffold to enhance the SENP1-EIF3I interaction. As a result, the SUMOylation of EIF3I is inhibited, preventing its ubiquitin-mediated degradation. Ultimately, this activates the Wnt/ß-catenin signaling pathway, stimulating EMT and metastasis in HCC. Our findings shed light on the regulatory mechanism of lnc-TSPAN12 in HCC metastasis and identify the lnc-TSPAN12-EIF3I/SENP1 axis as a novel therapeutic target for HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , RNA Longo não Codificante , Tetraspaninas , Humanos , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Transição Epitelial-Mesenquimal , Fator de Iniciação 3 em Eucariotos/genética , Fator de Iniciação 3 em Eucariotos/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/patologia , Metiltransferases/genética , Metiltransferases/metabolismo , RNA Longo não Codificante/genética , Via de Sinalização Wnt
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