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1.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204592

RESUMO

NADH dehydrogenase (ubiquinone) Fe-S protein 8 (NDUFS8) is a nuclear-encoded core subunit of human mitochondrial complex I. Defects in NDUFS8 are associated with Leigh syndrome and encephalomyopathy. Cell-penetrating peptide derived from the HIV-1 transactivator of transcription protein (TAT) has been successfully applied as a carrier to bring fusion proteins into cells without compromising the biological function of the cargoes. In this study, we developed a TAT-mediated protein transduction system to rescue complex I deficiency caused by NDUFS8 defects. Two fusion proteins (TAT-NDUFS8 and NDUFS8-TAT) were exogenously expressed and purified from Escherichia coli for transduction of human cells. In addition, similar constructs were generated and used in transfection studies for comparison. The results showed that both exogenous TAT-NDUFS8 and NDUFS8-TAT were delivered into mitochondria and correctly processed. Interestingly, the mitochondrial import of TAT-containing NDUFS8 was independent of mitochondrial membrane potential. Treatment with TAT-NDUFS8 not only significantly improved the assembly of complex I in an NDUFS8-deficient cell line, but also partially rescued complex I functions both in the in-gel activity assay and the oxygen consumption assay. Our current findings suggest the considerable potential of applying the TAT-mediated protein transduction system for treatment of complex I deficiency.


Assuntos
Complexo I de Transporte de Elétrons/deficiência , Potencial da Membrana Mitocondrial , Mitocôndrias/genética , Mitocôndrias/metabolismo , NADH Desidrogenase/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismo , Sequência de Aminoácidos , Linhagem Celular , Sobrevivência Celular , Células Cultivadas , Complexo de Proteínas da Cadeia de Transporte de Elétrons/genética , Complexo de Proteínas da Cadeia de Transporte de Elétrons/metabolismo , Humanos , Mitocôndrias/efeitos dos fármacos , NADH Desidrogenase/genética , Transporte Proteico , Interferência de RNA , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacologia , Produtos do Gene tat do Vírus da Imunodeficiência Humana/genética
2.
FASEB J ; 35(8): e21681, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34196428

RESUMO

The sodium/iodide symporter (NIS) expresses at the basolateral plasma membrane of the thyroid follicular cell and mediates iodide accumulation required for normal thyroid hormonogenesis. Loss-of-function NIS variants cause congenital hypothyroidism due to impaired iodide accumulation in thyroid follicular cells underscoring the significance of NIS for thyroid physiology. Here we report novel findings derived from the thorough characterization of the nonsense NIS mutant p.R636* NIS-leading to a truncated protein missing the last eight amino acids-identified in twins with congenital hypothyroidism. R636* NIS is severely mislocalized into intracellular vesicular compartments due to the lack of a conserved carboxy-terminal type 1 PDZ-binding motif. As a result, R636* NIS is barely targeted to the plasma membrane and therefore iodide transport is reduced. Deletion of the PDZ-binding motif causes NIS accumulation into late endosomes and lysosomes. Using PDZ domain arrays, we revealed that the PDZ-domain containing protein SCRIB binds to the carboxy-terminus of NIS by a PDZ-PDZ interaction. Furthermore, in CRISPR/Cas9-based SCRIB deficient cells, NIS expression at the basolateral plasma membrane is compromised, leading to NIS localization into intracellular vesicular compartments. We conclude that the PDZ-binding motif is a plasma membrane retention signal that participates in the polarized expression of NIS by selectively interacting with the PDZ-domain containing protein SCRIB, thus retaining the transporter at the basolateral plasma membrane. Our data provide insights into the molecular mechanisms that regulate NIS expression at the plasma membrane, a topic of great interest in the thyroid cancer field considering the relevance of NIS-mediated radioactive iodide therapy for differentiated thyroid carcinoma.


Assuntos
Proteínas de Membrana/metabolismo , Simportadores/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular , Membrana Celular/metabolismo , Códon sem Sentido , Hipotireoidismo Congênito/genética , Hipotireoidismo Congênito/metabolismo , Sequência Conservada , Cães , Endossomos/metabolismo , Células HEK293 , Humanos , Lisossomos/metabolismo , Células Madin Darby de Rim Canino , Proteínas de Membrana/química , Proteínas de Membrana/genética , Modelos Moleculares , Mutagênese Sítio-Dirigida , Domínios PDZ/genética , Estrutura Secundária de Proteína , Ratos , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Simportadores/química , Simportadores/genética , Glândula Tireoide/metabolismo , Proteínas Supressoras de Tumor/química , Proteínas Supressoras de Tumor/genética
3.
Nat Commun ; 12(1): 3388, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099676

RESUMO

Wearable smart electronic devices, such as smart watches, are generally equipped with green-light-emitting diodes, which are used for photoplethysmography to monitor a panoply of physical health parameters. Here, we present a traceless, green-light-operated, smart-watch-controlled mammalian gene switch (Glow Control), composed of an engineered membrane-tethered green-light-sensitive cobalamin-binding domain of Thermus thermophilus (TtCBD) CarH protein in combination with a synthetic cytosolic TtCBD-transactivator fusion protein, which manage translocation of TtCBD-transactivator into the nucleus to trigger expression of transgenes upon illumination. We show that Apple-Watch-programmed percutaneous remote control of implanted Glow-controlled engineered human cells can effectively treat experimental type-2 diabetes by producing and releasing human glucagon-like peptide-1 on demand. Directly interfacing wearable smart electronic devices with therapeutic gene expression will advance next-generation personalized therapies by linking biopharmaceutical interventions to the internet of things.


Assuntos
Proteínas de Bactérias/efeitos da radiação , Diabetes Mellitus Tipo 2/terapia , Peptídeo 1 Semelhante ao Glucagon/uso terapêutico , Optogenética/métodos , Transativadores/efeitos da radiação , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Engenharia Celular , Diabetes Mellitus Tipo 2/genética , Feminino , Engenharia Genética , Peptídeo 1 Semelhante ao Glucagon/genética , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Células HEK293 , Humanos , Luz , Masculino , Células-Tronco Mesenquimais , Camundongos , Camundongos Obesos , Optogenética/instrumentação , Fotopletismografia/instrumentação , Domínios Proteicos/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/efeitos da radiação , Thermus thermophilus/genética , Transativadores/genética , Transativadores/metabolismo , Transgenes , Dispositivos Eletrônicos Vestíveis
4.
Methods Mol Biol ; 2268: 61-76, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34085261

RESUMO

G protein-coupled receptors (GPCR) are integral membrane proteins that regulate multiple cellular processes. To obtain insights into structural properties of GPCR and mechanism of activity, these proteins should be isolated in significant (milligram) quantities, in a pure, homogenous, and stable form. Here we describe the expression and purification of type II human cannabinoid receptor CB2, a class A GPCR, in two different types of expression hosts: in Escherichia coli and in mammalian suspension cell culture Expi293. Our method allows preparation of milligram quantities of the purified receptors suitable for a wide array of downstream applications including high-resolution structural studies and functional assays.


Assuntos
Cromatografia de Afinidade/métodos , Cristalografia por Raios X/métodos , Ressonância Magnética Nuclear Biomolecular/métodos , Receptor CB2 de Canabinoide/isolamento & purificação , Receptor CB2 de Canabinoide/metabolismo , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismo , Detergentes/química , Escherichia coli/genética , Escherichia coli/metabolismo , Células HEK293 , Humanos , Receptor CB2 de Canabinoide/genética , Proteínas Recombinantes de Fusão/genética
5.
Int J Mol Sci ; 22(11)2021 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-34067464

RESUMO

Background: Spindle cell rhabdomyosarcoma (S-RMS) is a rare tumor that was previously considered as an uncommon variant of embryonal RMS (ERMS) and recently reclassified as a distinct RMS subtype with NCOA2, NCOA1, and VGLL2 fusion genes. In this study, we established a cell line (S-RMS1) derived from a four-month-old boy with infantile spindle cell RMS harboring SRF-NCOA2 gene fusion. Methods: Morphological and molecular characteristics of S-RMS1 were analyzed and compared with two RMS cell lines, RH30 and RD18. Whole genome sequencing of S-RMS1 and clinical exome sequencing of genomic DNA were performed. Results: S-RMS1 showed cells small in size, with a fibroblast-like morphology and positivity for MyoD-1, myogenin, desmin, and smooth muscle actin. The population doubling time was 3.7 days. Whole genome sequencing demonstrated that S-RMS1 retained the same genetic profile of the tumor at diagnosis. A Western blot analysis showed downregulation of AKT-p and YAP-p while RT-qPCR showed upregulation of endoglin and GATA6 as well as downregulation of TGFßR1 and Mef2C transcripts. Conclusion: This is the first report of the establishment of a cell line from an infantile spindle cell RMS with SRF-NCOA2 gene fusion. S-RMS1 should represent a useful tool for the molecular characterization of this rare and almost unknown tumor.


Assuntos
Fusão Gênica/genética , Coativador 2 de Receptor Nuclear/genética , Proteínas Recombinantes de Fusão/genética , Rabdomiossarcoma/genética , Fator de Resposta Sérica/genética , Adulto , Linhagem Celular , Criança , Pré-Escolar , Regulação para Baixo/genética , Exoma/genética , Feminino , Humanos , Lactente , Masculino , Miogenina/genética , Coativador 1 de Receptor Nuclear/genética , Adulto Jovem
6.
Sci Adv ; 7(22)2021 05.
Artigo em Inglês | MEDLINE | ID: covidwho-1247308

RESUMO

Since the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), various vaccines are being developed, with most vaccine candidates focusing on the viral spike protein. Here, we developed a previously unknown subunit vaccine comprising the receptor binding domain (RBD) of the spike protein fused with the tetanus toxoid epitope P2 (RBD-P2) and tested its efficacy in rodents and nonhuman primates (NHPs). We also investigated whether the SARS-CoV-2 nucleocapsid protein (N) could increase vaccine efficacy. Immunization with N and RBD-P2 (RBDP2/N) + alum increased T cell responses in mice and neutralizing antibody levels in rats compared with those obtained using RBD-P2 + alum. Furthermore, in NHPs, RBD-P2/N + alum induced slightly faster SARS-CoV-2 clearance than that induced by RBD-P2 + alum, albeit without statistical significance. Our study supports further development of RBD-P2 as a vaccine candidate against SARS-CoV-2. Also, it provides insights regarding the use of N in protein-based vaccines against SARS-CoV-2.


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Proteínas Recombinantes de Fusão/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Toxoide Tetânico/imunologia , Animais , COVID-19/genética , COVID-19/imunologia , Vacinas contra COVID-19/genética , Chlorocebus aethiops , Proteínas do Nucleocapsídeo de Coronavírus/genética , Feminino , Macaca fascicularis , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Fosfoproteínas/genética , Fosfoproteínas/imunologia , Domínios Proteicos , Ratos , Proteínas Recombinantes de Fusão/genética , SARS-CoV-2/genética , Células Sf9 , Glicoproteína da Espícula de Coronavírus/genética , Spodoptera , Toxoide Tetânico/genética , Células Vero
7.
Sci Adv ; 7(22)2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34049881

RESUMO

Since the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), various vaccines are being developed, with most vaccine candidates focusing on the viral spike protein. Here, we developed a previously unknown subunit vaccine comprising the receptor binding domain (RBD) of the spike protein fused with the tetanus toxoid epitope P2 (RBD-P2) and tested its efficacy in rodents and nonhuman primates (NHPs). We also investigated whether the SARS-CoV-2 nucleocapsid protein (N) could increase vaccine efficacy. Immunization with N and RBD-P2 (RBDP2/N) + alum increased T cell responses in mice and neutralizing antibody levels in rats compared with those obtained using RBD-P2 + alum. Furthermore, in NHPs, RBD-P2/N + alum induced slightly faster SARS-CoV-2 clearance than that induced by RBD-P2 + alum, albeit without statistical significance. Our study supports further development of RBD-P2 as a vaccine candidate against SARS-CoV-2. Also, it provides insights regarding the use of N in protein-based vaccines against SARS-CoV-2.


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Proteínas Recombinantes de Fusão/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Toxoide Tetânico/imunologia , Animais , COVID-19/genética , COVID-19/imunologia , Vacinas contra COVID-19/genética , Chlorocebus aethiops , Proteínas do Nucleocapsídeo de Coronavírus/genética , Feminino , Macaca fascicularis , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Fosfoproteínas/genética , Fosfoproteínas/imunologia , Domínios Proteicos , Ratos , Proteínas Recombinantes de Fusão/genética , SARS-CoV-2/genética , Células Sf9 , Glicoproteína da Espícula de Coronavírus/genética , Spodoptera , Toxoide Tetânico/genética , Células Vero
8.
Nat Commun ; 12(1): 2792, 2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33990599

RESUMO

ASH1L histone methyltransferase plays a crucial role in the pathogenesis of different diseases, including acute leukemia. While ASH1L represents an attractive drug target, developing ASH1L inhibitors is challenging, as the catalytic SET domain adapts an inactive conformation with autoinhibitory loop blocking the access to the active site. Here, by applying fragment-based screening followed by medicinal chemistry and a structure-based design, we developed first-in-class small molecule inhibitors of the ASH1L SET domain. The crystal structures of ASH1L-inhibitor complexes reveal compound binding to the autoinhibitory loop region in the SET domain. When tested in MLL leukemia models, our lead compound, AS-99, blocks cell proliferation, induces apoptosis and differentiation, downregulates MLL fusion target genes, and reduces the leukemia burden in vivo. This work validates the ASH1L SET domain as a druggable target and provides a chemical probe to further study the biological functions of ASH1L as well as to develop therapeutic agents.


Assuntos
Antineoplásicos/farmacologia , Proteínas de Ligação a DNA/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Leucemia/tratamento farmacológico , Leucemia/enzimologia , Animais , Antineoplásicos/química , Domínio Catalítico/efeitos dos fármacos , Domínio Catalítico/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Cristalografia por Raios X , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Desenho de Fármacos , Descoberta de Drogas , Inibidores Enzimáticos/química , Feminino , Histona-Lisina N-Metiltransferase/química , Histona-Lisina N-Metiltransferase/genética , Humanos , Leucemia/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Moleculares , Proteína de Leucina Linfoide-Mieloide/genética , Oncogenes , Domínios Proteicos , Proteínas Recombinantes de Fusão/genética
9.
Nat Commun ; 12(1): 2999, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-34016966

RESUMO

The proper functional interaction between different tissues represents a key component in systemic metabolic control. Indeed, disruption of endocrine inter-tissue communication is a hallmark of severe metabolic dysfunction in obesity and diabetes. Here, we show that the FNDC4-GPR116, liver-white adipose tissue endocrine axis controls glucose homeostasis. We found that the liver primarily controlled the circulating levels of soluble FNDC4 (sFNDC4) and lowering of the hepatokine FNDC4 led to prediabetes in mice. Further, we identified the orphan adhesion GPCR GPR116 as a receptor of sFNDC4 in the white adipose tissue. Upon direct and high affinity binding of sFNDC4 to GPR116, sFNDC4 promoted insulin signaling and insulin-mediated glucose uptake in white adipocytes. Indeed, supplementation with FcsFNDC4 in prediabetic mice improved glucose tolerance and inflammatory markers in a white-adipocyte selective and GPR116-dependent manner. Of note, the sFNDC4-GPR116, liver-adipose tissue axis was dampened in (pre) diabetic human patients. Thus our findings will now allow for harnessing this endocrine circuit for alternative therapeutic strategies in obesity-related pre-diabetes.


Assuntos
Tecido Adiposo Branco/metabolismo , Proteínas de Membrana/metabolismo , Estado Pré-Diabético/metabolismo , Proteínas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Células 3T3-L1 , Adipócitos/metabolismo , Tecido Adiposo Branco/citologia , Adolescente , Adulto , Idoso , Animais , Células CHO , Estudos de Coortes , Cricetulus , Estudos Transversais , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/prevenção & controle , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Feminino , Técnicas de Silenciamento de Genes , Glucose/metabolismo , Células HEK293 , Células Hep G2 , Humanos , Insulina/metabolismo , Resistência à Insulina , Ilhotas Pancreáticas/metabolismo , Fígado/metabolismo , Masculino , Proteínas de Membrana/administração & dosagem , Proteínas de Membrana/sangue , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Células NIH 3T3 , Estado Pré-Diabético/sangue , Estado Pré-Diabético/tratamento farmacológico , Estado Pré-Diabético/etiologia , Cultura Primária de Células , Proteínas/análise , Receptores Acoplados a Proteínas G/sangue , Receptores Acoplados a Proteínas G/genética , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Adulto Jovem
10.
Int J Mol Sci ; 22(9)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33947115

RESUMO

Cortisol, a stress hormone, plays key roles in mediating stress and anti-inflammatory responses. As abnormal cortisol levels can induce various adverse effects, screening cortisol and cortisol analogues is important for monitoring stress levels and for identifying drug candidates. A novel cell-based sensing system was adopted for rapid screening of cortisol and its functional analogues under complex cellular regulation. We used glucocorticoid receptor (GR) fused to a split intein which reconstituted with the counterpart to trigger conditional protein splicing (CPS) in the presence of targets. CPS generates functional signal peptides which promptly translocate the fluorescent cargo. The sensor cells exhibited exceptional performance in discriminating between the functional and structural analogues of cortisol with improved sensitivity. Essential oil extracts with stress relief activity were screened using the sensor cells to identify GR effectors. The sensor cells responded to peppermint oil, and L-limonene and L-menthol were identified as potential GR effectors from the major components of peppermint oil. Further analysis indicated L-limonene as a selective GR agonist (SEGRA) which is a potential anti-inflammatory agent as it attenuates proinflammatory responses without causing notable adverse effects of GR agonists.


Assuntos
Técnicas Biossensoriais , Avaliação Pré-Clínica de Medicamentos/métodos , Polarização de Fluorescência/métodos , Hidrocortisona/análise , Óleos Voláteis/farmacologia , Receptores de Glucocorticoides/agonistas , Atrofia , Acetato de Ciproterona/farmacologia , Dexametasona/farmacologia , Estradiol/farmacologia , Fluorometria , Células HeLa , Humanos , Inteínas , Limoneno/farmacologia , Proteínas Luminescentes/análise , Mentol/farmacologia , Mifepristona/farmacologia , Estrutura Molecular , Músculo Esquelético/patologia , Mioblastos/efeitos dos fármacos , Óleos Vegetais/farmacologia , Processamento de Proteína , Transporte Proteico , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
11.
Appl Microbiol Biotechnol ; 105(10): 4167-4175, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33939024

RESUMO

Somatostatin (SS) is one of the peptide hormones that regulate the endocrine system in animals. When SS is used to immunize animals, the correspondingly generated anti-SS antibody neutralizes the SS and, therefore, alleviates its growth inhibiting effects. This is of great value to the livestock industry; however, previously developed methods fail to obtain enough recombinant SS in an economical way. Herein, we describe the employment of a commonly used feed enzyme, i.e., xylanase, as a carrier protein for recombinant expression of SS in large quantity. The SS gene was fused to one of the two xylanase genes (XynCDBFV and BsXynC) and recombinantly expressed in Pichia pastoris. The purified xylanase-SS fusion proteins displayed excellent antigenicity and immunogenicity. In addition, they retained the enzymatic activities and thermostability of the xylanases, indicating that they can catalyze hydrolysis of xylan in plant cell wall of the animal feeds and stand the high temperature in feed pelleting. Thus, the xylanase-SS fusion proteins serve as an excellent candidate chimeric bifunctional vaccine-feed enzyme protein retaining both SS immunogenicity and xylanase activity. KEY POINTS: • Somatostatin is expressed in P. pastoris as fusion proteins with two xylanases. • The chimeric proteins retain both immunogenicity and xylanase activity. • The xylanase-SS proteins may serve as bifunctional proteins in livestock industry.


Assuntos
Endo-1,4-beta-Xilanases , Pichia , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/metabolismo , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Pichia/genética , Pichia/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes/genética , Saccharomycetales , Somatostatina/genética
12.
Anal Chim Acta ; 1161: 238180, 2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-33896564

RESUMO

Enzyme-linked immunosorbent assays (ELISAs) are essential for monitoring various biomarkers. Competitive and noncompetitive (sandwich) assay formats are used to determine hapten and macromolecule levels, respectively. Both formats require more sensitive detection of reporter enzymes for greater assay sensitivities. We previously reported the utility of wild-type Gaussia luciferase (wtGLuc) as a fusion partner with antibody single-chain Fv fragments (scFvs) for developing sensitive luminescent ELISAs. Here, we evaluated utility of NanoLuc luciferase (NLuc), a recently developed luciferase, as fusion partner with scFvs from the view of comparison with wtGLuc and a mutant of alkaline phosphatase (ALP'). Thyroxine (T4) and T4-labeled albumin were chosen as model haptenic and macromolecular antigens, respectively. An in-house-prepared anti-T4 scFv was fused with NLuc, wtGLuc, or ALP'. The scFv-NLuc fusion protein showed 47-fold and 29-fold lower limit of detection [LOD; 59 zmol (per assay)] than the wtGLuc- and ALP'-fusions, respectively. In a competitive T4 ELISA, the NLuc-fusion showed 9.3- and 6.3-fold lower LOD, (0.67 pg) than the wtGLuc- and ALP'-fusions, respectively, with a higher specificity in clinical applications. A typical colorimetric ELISA using a peroxidase-labeled second antibody showed 70-fold higher LOD than NLuc-based ELISA. Another advantage of the NLuc-fusion was shown in the sandwich assays; the LOD of T4-labeled albumin (5.0 fmol) was >6-fold lower than that of the other luminescent ELISAs. In an additional sandwich assay developed to count bacteriophage particles, NLuc enabled more sensitive determination than wtGLuc, whereas ALP' showed nearly equivalent performance. Its slowest alteration rate for light intensity after starting the enzyme reaction should enable robust batch-by-batch assay operations. Thus, we concluded that scFv-NLuc fusions serve as suitable probes in various types of immunoassays and may facilitate higher sensitivities with practical specificities.


Assuntos
Haptenos , Fragmentos de Imunoglobulinas , Ensaio de Imunoadsorção Enzimática , Imunoensaio , Luciferases/genética , Proteínas Recombinantes de Fusão/genética
13.
Biochem Biophys Res Commun ; 558: 79-85, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: covidwho-1193239

RESUMO

During 2020, the COVID-19 pandemic affected almost 108 individuals. Quite a number of vaccines against COVID-19 were therefore developed, and a few recently received authorization for emergency use. Overall, these vaccines target specific viral proteins by antibodies whose synthesis is directly elicited or indirectly triggered by nucleic acids coding for the desired targets. Among these targets, the receptor binding domain (RBD) of COVID-19 spike protein (SP) does frequently occur in the repertoire of candidate vaccines. However, the immunogenicity of RBD per se is limited by its low molecular mass, and by a structural rearrangement of full-length SP accompanied by the detachment of RBD. Here we show that the RBD of COVID-19 SP can be conveniently produced in Escherichia coli when fused to a fragment of CRM197, a variant of diphtheria toxin currently used for a number of conjugated vaccines. In particular, we show that the CRM197-RBD chimera solubilized from inclusion bodies can be refolded and purified to a state featuring the 5 native disulphide bonds of the parental proteins, the competence in binding angiotensin-converting enzyme 2, and a satisfactory stability at room temperature. Accordingly, our observations provide compulsory information for the development of a candidate vaccine directed against COVID-19.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Escherichia coli , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/isolamento & purificação , Sequência de Bases , Vacinas contra COVID-19/química , Vacinas contra COVID-19/genética , Vacinas contra COVID-19/imunologia , Escherichia coli/genética , Escherichia coli/metabolismo , Corpos de Inclusão/química , Corpos de Inclusão/metabolismo , Espectrometria de Massas , Modelos Moleculares , Redobramento de Proteína , Estabilidade Proteica , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/isolamento & purificação , SARS-CoV-2/química , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/biossíntese , Glicoproteína da Espícula de Coronavírus/isolamento & purificação , Temperatura , Fatores de Tempo
14.
Biochem Biophys Res Commun ; 558: 79-85, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-33906110

RESUMO

During 2020, the COVID-19 pandemic affected almost 108 individuals. Quite a number of vaccines against COVID-19 were therefore developed, and a few recently received authorization for emergency use. Overall, these vaccines target specific viral proteins by antibodies whose synthesis is directly elicited or indirectly triggered by nucleic acids coding for the desired targets. Among these targets, the receptor binding domain (RBD) of COVID-19 spike protein (SP) does frequently occur in the repertoire of candidate vaccines. However, the immunogenicity of RBD per se is limited by its low molecular mass, and by a structural rearrangement of full-length SP accompanied by the detachment of RBD. Here we show that the RBD of COVID-19 SP can be conveniently produced in Escherichia coli when fused to a fragment of CRM197, a variant of diphtheria toxin currently used for a number of conjugated vaccines. In particular, we show that the CRM197-RBD chimera solubilized from inclusion bodies can be refolded and purified to a state featuring the 5 native disulphide bonds of the parental proteins, the competence in binding angiotensin-converting enzyme 2, and a satisfactory stability at room temperature. Accordingly, our observations provide compulsory information for the development of a candidate vaccine directed against COVID-19.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Escherichia coli , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/isolamento & purificação , Sequência de Bases , Vacinas contra COVID-19/química , Vacinas contra COVID-19/genética , Vacinas contra COVID-19/imunologia , Escherichia coli/genética , Escherichia coli/metabolismo , Corpos de Inclusão/química , Corpos de Inclusão/metabolismo , Espectrometria de Massas , Modelos Moleculares , Redobramento de Proteína , Estabilidade Proteica , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/isolamento & purificação , SARS-CoV-2/química , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/biossíntese , Glicoproteína da Espícula de Coronavírus/isolamento & purificação , Temperatura , Fatores de Tempo
15.
J Agric Food Chem ; 69(17): 5086-5095, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33882667

RESUMO

In this study, some novel plasmids have been constructed for flexible and zero-background molecular cloning, more efficient expression, and purification of proteins with improved strategies. The plasmids pANY4-pL18-ccdB and pANY4-pR18/pL18-ccdB have different promoters in the complementary DNA strands. Therefore, recombinant plasmids for either isopropyl-ß-d-thiogalactoside-induced or temperature-induced protein expression could be simultaneously constructed in a single molecular cloning process for parallel comparison. Intriguingly, the mutated pL18 and pR18/pL18 promoters performed similar to or even better than the T7 promoter when used for promoting the expression of the GFP or pfLamA enzyme. Moreover, the plasmid pANY8 containing the His-elastin-like polypeptide (ELP)-intein multifunctional tag was constructed, and special purification protocol was designed to obtain purified proteins without the requirement of time-consuming dialysis steps to remove imidazole and high concentration of salt ions. Additionally, the urea-based denaturation and refolding processes can be conveniently integrated into the ELP-mediated precipitation protocol for purification of insoluble inclusion bodies, omitting the time-consuming dialysis steps.


Assuntos
Escherichia coli , Inteínas , Clonagem Molecular , Elastina , Escherichia coli/genética , Vetores Genéticos/genética , Plasmídeos/genética , Proteínas Recombinantes de Fusão/genética
16.
Molecules ; 26(6)2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33808840

RESUMO

α-l-arabinofuranosidase is a subfamily of glycosidases involved in the hydrolysis of l-arabinofuranosidic bonds, especially in those of the terminal non-reducing arabinofuranosyl residues of glycosides, from which efficient glycoside hydrolases can be screened for the transformation of ginsenosides. In this study, the ginsenoside Rc-hydrolyzing α-l-arabinofuranosidase gene, BsAbfA, was cloned from Bacilus subtilis, and its codons were optimized for efficient expression in E. coli BL21 (DE3). The recombinant protein BsAbfA fused with an N-terminal His-tag was overexpressed and purified, and then subjected to enzymatic characterization. Site-directed mutagenesis of BsAbfA was performed to verify the catalytic site, and the molecular mechanism of BsAbfA catalyzing ginsenoside Rc was analyzed by molecular docking, using the homology model of sequence alignment with other ß-glycosidases. The results show that the purified BsAbfA had a specific activity of 32.6 U/mg. Under optimal conditions (pH 5, 40 °C), the kinetic parameters Km of BsAbfA for pNP-α-Araf and ginsenoside Rc were 0.6 mM and 0.4 mM, while the Kcat/Km were 181.5 s-1 mM-1 and 197.8 s-1 mM-1, respectively. More than 90% of ginsenoside Rc could be transformed by 12 U/mL purified BsAbfA at 40 °C and pH 5 in 24 h. The results of molecular docking and site-directed mutagenesis suggested that the E173 and E292 variants for BsAbfA are important in recognizing ginsenoside Rc effectively, and to make it enter the active pocket to hydrolyze the outer arabinofuranosyl moieties at C20 position. These remarkable properties and the catalytic mechanism of BsAbfA provide a good alternative for the effective biotransformation of the major ginsenoside Rc into Rd.


Assuntos
Substituição de Aminoácidos , Bacillus subtilis , Proteínas de Bactérias , Ginsenosídeos/química , Glicosídeo Hidrolases , Mutagênese Sítio-Dirigida , Bacillus subtilis/enzimologia , Bacillus subtilis/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/genética , Mutação de Sentido Incorreto , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética
17.
Nat Commun ; 12(1): 2287, 2021 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-33863894

RESUMO

Both adenine base editors (ABEs) and cytosine base editors (CBEs) have been recently revealed to induce transcriptome-wide RNA off-target editing in a guide RNA-independent manner. Here we construct a reporter system containing E.coli Hokb gene with a tRNA-like motif for robust detection of RNA editing activities as the optimized ABE, ABEmax, induces highly efficient A-to-I (inosine) editing within an E.coli tRNA-like structure. Then, we design mutations to disrupt the potential interaction between TadA and tRNAs in structure-guided principles and find that Arginine 153 (R153) within TadA is essential for deaminating RNAs with core tRNA-like structures. Two ABEmax or mini ABEmax variants (TadA* fused with Cas9n) with deletion of R153 within TadA and/or TadA* (named as del153/del153* and mini del153) are successfully engineered, showing minimized RNA off-targeting, but comparable DNA on-targeting activities. Moreover, R153 deletion in recently reported ABE8e or ABE8s can also largely reduce their RNA off-targeting activities. Taken together, we develop a strategy to generate engineered ABEs (eABEs) with minimized RNA off-targeting activities.


Assuntos
Adenosina Desaminase/genética , Proteína 9 Associada à CRISPR/genética , DNA/genética , Proteínas de Escherichia coli/genética , Edição de Genes/métodos , Adenina/metabolismo , Adenosina Desaminase/metabolismo , Toxinas Bacterianas/genética , Proteína 9 Associada à CRISPR/metabolismo , Linhagem Celular Tumoral , Citosina/metabolismo , DNA/metabolismo , Proteínas de Escherichia coli/metabolismo , Genes Reporter , Células HEK293 , Humanos , Inosina/genética , Inosina/metabolismo , Engenharia de Proteínas , Edição de RNA/genética , RNA de Transferência/genética , RNA de Transferência/metabolismo , RNA-Seq , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
18.
SLAS Discov ; 26(6): 749-756, 2021 07.
Artigo em Inglês | MEDLINE | ID: covidwho-1136206

RESUMO

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) represents a significant threat to human health. Despite its similarity to related coronaviruses, there are currently no specific treatments for COVID-19 infection, and therefore there is an urgent need to develop therapies for this and future coronavirus outbreaks. Formation of the cap at the 5' end of viral RNA has been shown to help coronaviruses evade host defenses. Nonstructural protein 14 (nsp14) is responsible for N7-methylation of the cap guanosine in coronaviruses. This enzyme is highly conserved among coronaviruses and is a bifunctional protein with both N7-methyltransferase and 3'-5' exonuclease activities that distinguish nsp14 from its human equivalent. Mutational analysis of SARS-CoV nsp14 highlighted its role in viral replication and translation efficiency of the viral genome. In this paper, we describe the characterization and development of a high-throughput assay for nsp14 utilizing RapidFire technology. The assay has been used to screen a library of 1771 Food and Drug Administration (FDA)-approved drugs. From this, we have validated nitazoxanide as a selective inhibitor of the methyltransferase activity of nsp14. Although modestly active, this compound could serve as a starting point for further optimization.


Assuntos
Antivirais/farmacologia , Exorribonucleases/antagonistas & inibidores , Ensaios de Triagem em Larga Escala , Nitrocompostos/farmacologia , Capuzes de RNA/antagonistas & inibidores , RNA Viral/antagonistas & inibidores , SARS-CoV-2/efeitos dos fármacos , Tiazóis/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Antiparasitários/química , Antiparasitários/farmacologia , Antivirais/química , COVID-19/virologia , Clonagem Molecular , Reposicionamento de Medicamentos , Ensaios Enzimáticos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Escherichia coli/genética , Escherichia coli/metabolismo , Exorribonucleases/genética , Exorribonucleases/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Humanos , Cinética , Espectrometria de Massas/métodos , Metilação , Nitrocompostos/química , Medicamentos sob Prescrição/química , Medicamentos sob Prescrição/farmacologia , Capuzes de RNA/genética , Capuzes de RNA/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , SARS-CoV-2/enzimologia , SARS-CoV-2/genética , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Tiazóis/química , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacos
19.
PLoS Pathog ; 17(3): e1009328, 2021 03.
Artigo em Inglês | MEDLINE | ID: covidwho-1115314

RESUMO

A key step to the SARS-CoV-2 infection is the attachment of its Spike receptor-binding domain (S RBD) to the host receptor ACE2. Considerable research has been devoted to the development of neutralizing antibodies, including llama-derived single-chain nanobodies, to target the receptor-binding motif (RBM) and to block ACE2-RBD binding. Simple and effective strategies to increase potency are desirable for such studies when antibodies are only modestly effective. Here, we identify and characterize a high-affinity synthetic nanobody (sybody, SR31) as a fusion partner to improve the potency of RBM-antibodies. Crystallographic studies reveal that SR31 binds to RBD at a conserved and 'greasy' site distal to RBM. Although SR31 distorts RBD at the interface, it does not perturb the RBM conformation, hence displaying no neutralizing activities itself. However, fusing SR31 to two modestly neutralizing sybodies dramatically increases their affinity for RBD and neutralization activity against SARS-CoV-2 pseudovirus. Our work presents a tool protein and an efficient strategy to improve nanobody potency.


Assuntos
Enzima de Conversão de Angiotensina 2/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , SARS-CoV-2/imunologia , Anticorpos de Domínio Único/imunologia , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/genética , Anticorpos Antivirais/química , Anticorpos Antivirais/genética , Afinidade de Anticorpos , Sítios de Ligação , Cristalografia por Raios X , Células HEK293 , Humanos , Modelos Moleculares , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Anticorpos de Domínio Único/química , Anticorpos de Domínio Único/genética
20.
Biol Cell ; 113(7): 311-328, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33666950

RESUMO

BACKGROUND INFORMATION: Comprehensive libraries of plasmids for SARS-CoV-2 proteins with various tags (e.g., Strep, HA, Turbo) are now available. They enable the identification of numerous potential protein-protein interactions between the SARS-CoV-2 virus and host proteins. RESULTS: We present here a large library of SARS CoV-2 protein constructs fused with green and red fluorescent proteins and their initial characterisation in various human cell lines including lung epithelial cell models (A549, BEAS-2B), as well as in budding yeast. The localisation of a few SARS-CoV-2 proteins matches their proposed interactions with host proteins. These include the localisation of Nsp13 to the centrosome, Orf3a to late endosomes and Orf9b to mitochondria. CONCLUSIONS AND SIGNIFICANCE: This library should facilitate further cellular investigations, notably by imaging techniques.


Assuntos
COVID-19/virologia , Biblioteca de Peptídeos , SARS-CoV-2/metabolismo , Proteínas Virais/metabolismo , Células A549 , Linhagem Celular , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Interações entre Hospedeiro e Microrganismos/fisiologia , Humanos , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microscopia de Fluorescência , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , SARS-CoV-2/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Imagem com Lapso de Tempo , Proteínas Virais/genética
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