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1.
World J Microbiol Biotechnol ; 35(9): 135, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31432264

RESUMO

The feather-degrading strain Thermoactinomyces sp. YT06 secretes an extracellular keratinolytic protease (KERTYT); however, the gene encoding this protease remains unknown. The kerT1 gene (1170 bp) encoding keratinase was cloned and expressed in Escherichia coli BL21(DE3). Purified recombinant keratinase (rKERTYT) was achieved at a yield of 39.16% and 65.27-fold purification with a specific activity of 1325 U/mg. It was shown that rKERTYT has many similarities to the native enzyme (KERTYT) by characterization of rKERTYT. The molecular weight of rKERTYT secreted by recombinant E. coli was approximately 28 kDa. The optimal temperature and the pH values of rKERTYT were 65 °C and 8.5, respectively, and the protein remained stable from 50 to 60 °C and pH 6-11. The keratinase was strongly inhibited by phenyl methane sulfonyl fluoride (PMSF), suggesting that it belongs to the serine protease family. It was significantly activated by Mn2+ and ß-mercaptoethanol (ß-Me). rKERTYT showed stability and retained over 80% activity with the existence of organic solvents such as acetone, methylbenzene and dimethyl sulfoxide. These findings indicated that rKERTYT will be a promising candidate for the enzymatic processing of keratinous wastes.


Assuntos
Clonagem Molecular , Escherichia coli/metabolismo , Expressão Gênica , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/metabolismo , Thermoactinomyces/enzimologia , Ativadores de Enzimas/análise , Inibidores Enzimáticos/análise , Estabilidade Enzimática , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Peso Molecular , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Temperatura Ambiente , Thermoactinomyces/genética
2.
World J Microbiol Biotechnol ; 35(7): 106, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31267229

RESUMO

Xenorhabdus nematophila HB310 secreted the insecticidal protein toxin complex. Two chitinase genes, chi60 and chi70, were found in X. nematophila toxin complex locus. In order to clarify the function of two chitinases, chi60 and chi70 genes were cloned and expressed in Escherichia coli Transetta (DE3). As a result, we found that the Chi60 and Chi70 belonged to glycoside hydrolases (GH) family 18 with a molecular mass of 65 kDa and 78 kDa, respectively. When colloidal chitin was treated as the substrate, Chi60 and Chi70 were proved to have the highest enzymatic activity at pH 6.0 and 50 °C. Chi60 and Chi70 had obvious growth inhibition effect against the second larvae of Helicoverpa armigera with growth inhibiting rate of 81.99% and 90.51%. Chi70 had synergistic effect with the insecticidal toxicity of Bt Cry 1Ac, but the Chi60 had no synergistic effect with Bt Cry 1Ac. Chi60 and Chi70 showed antifungal activity against Alternaria brassicicola, Verticillium dahliae and Coniothyrium diplodiella. The results increased our understanding of the chitinases produced by X. nematophila and laid a foundation for further studies on the mechanism of the chitinases.


Assuntos
Antifúngicos/farmacologia , Quitinases/antagonistas & inibidores , Quitinases/genética , Quitinases/metabolismo , Xenorhabdus/metabolismo , Alternaria/efeitos dos fármacos , Animais , Ascomicetos/efeitos dos fármacos , Quitina/metabolismo , Quitinases/classificação , Clonagem Molecular , Sinergismo Farmacológico , Ensaios Enzimáticos , Estabilidade Enzimática , Escherichia coli/genética , Expressão Gênica , Glicosídeo Hidrolases/genética , Concentração de Íons de Hidrogênio , Inseticidas/metabolismo , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Peso Molecular , Mariposas/efeitos dos fármacos , Mariposas/crescimento & desenvolvimento , Micotoxinas/genética , Micotoxinas/metabolismo , Filogenia , Domínios Proteicos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Temperatura Ambiente , Verticillium/efeitos dos fármacos , Xenorhabdus/genética
3.
DNA Cell Biol ; 38(8): 773-785, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31339741

RESUMO

Pierisin-5 protein (pie-5) belongs to a family of proteins possessing DNA-dependent ADP-ribosyltransferase activity, which can induce apoptotic cell death. The baculovirus-mediated expression vector system (BEVS) has been commonly used for in vitro expression of heterologous protein subunits for basic scientific research, in addition to the development and production of diagnostics and vaccines. In this study, a new method for the in vitro expression of the cytotoxic protein was established using the baculovirus expression system. The antiproliferative and apoptotic effect of the novel recombinant pierisin-5 protein (rpie-5) was investigated in different human cancer cell lines, such as HeLa, HepG2, and AGS. Cloning, in vitro overexpression, and purification of the rpie-5 protein were performed by using BEVS in Sf21 (Spodoptera frugiperda) insect cell line. The rpie-5 protein exhibits cytotoxicity in all the cell lines, but HeLa (IC50 0.6 µg/mL) was more sensitive when compared with HepG2 (IC50 1.9 µg/mL) and AGS (IC50 3.7 µg/mL) cell lines. The cytotoxic effects of rpie-5 lead to apoptotic cell death in cancer cells and resulted in nuclear fragmentation, enlargement of the nucleus, loss of mitochondrial membrane potential, and finally release of lactose dehydrogenase (LDH) enzyme from the cell membrane. This study reports the molecular mechanism of apoptotic cell death through the upregulation of Bax (Bcl-2 family activating protein-X), Bad, APAF-1 (apoptotic protease activating factor-1), Cyt-c, and caspase-3/9 and the downregulation of Bcl-2 (B-cell lymphoma 2) in rpie-5-treated cancer cells. The study concludes that rpie-5 has p53-independent apoptosis in HepG2 cells and p53-dependent apoptosis in HeLa and AGS cell lines. In the future, this study helps to understand the molecular mechanism of rpie-5 to induction of apoptosis and cell death.


Assuntos
ADP Ribose Transferases/farmacologia , Apoptose/efeitos dos fármacos , Proteínas de Insetos/farmacologia , Proteínas Recombinantes/farmacologia , ADP Ribose Transferases/genética , Animais , Apoptose/fisiologia , Baculoviridae/genética , Linhagem Celular Tumoral , Clonagem Molecular , Humanos , Proteínas de Insetos/genética , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Engenharia de Proteínas/métodos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Recombinantes/genética , Células Sf9 , Proteína Supressora de Tumor p53/genética , Proteína X Associada a bcl-2/genética
4.
World J Microbiol Biotechnol ; 35(8): 122, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31346836

RESUMO

To promote enzymatic unhairing for leather production, a new unhairing enzyme is developed. The Keratinase (kerT) gene, which is amplified from B. amyloliquefaciens TCCC11319 by PCR, is expressed in B. subtilis WB600. The recombinant KerT reduces the collagenolytic protease content as well as improving the keratinase content effectively. Therefore, the improved keratinase leads to the obviously unhairing effect, whereas the low collagenolytic protease ensures the integrity of collagen fibers in hide. It represents, the leather grain surface isn't destroyed thereby the value of finished leather can be maintained. In addition, by analyzing the properties of KerT, tits activity isn't inhibited with Na+, K+ and Ca2+ which are commonly used in leather production. The freeze-dried fermentation broth can be used directly as unhairing enzyme without addition of traditional sulfide chemicals. By evaluating the properties of unhaired hide, the results show that the collagen degradation ability of this new unhairing enzyme is slightly and it does not cause any adverse effects on the leather quality. Besides, this unhairing enzyme doesn't further degrade collagen in the time range of 8 h to 24 h, thus it is safely and easy-control in actual production. In conclusion, the enzymatic unhairing method with recombinant KerT has the potential to be more sustainable and efficient alternative than current sulphur-lime method, and it does not require the further purification thereby saving the cost.


Assuntos
Bacillus subtilis/enzimologia , Bacillus subtilis/genética , DNA Bacteriano/isolamento & purificação , Peptídeo Hidrolases/genética , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Fragmentação do DNA , DNA Bacteriano/genética , Fermentação , Regulação Bacteriana da Expressão Gênica , Genes Bacterianos , Peptídeo Hidrolases/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
5.
Gene ; 712: 143945, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31279712

RESUMO

Reactive oxygen species, generated in all the aerobic organisms, can cause oxidative stress. Excessive ROS may become a source of carcinogen due to DNA damage, lipid peroxidation, cell injury, and cell death. In order to prevent these adverse effects of ROS, antioxidant enzymes have evolved in aerobic organisms. Catalase is a major antioxidant enzyme that breaks down excessive H2O2 and inhibits apoptotic cell death. Here we molecularly characterized catalase from red-lip mullet. The cDNA sequence of LhCAT consists of an ORF of 1545 bp, which encodes a 527 amino acid peptide (~60 kDa). Based on bioinformatics analysis, LhCAT possesses a domain architecture characteristic of catalases, including a catalase proximal active site signature and a catalase proximal heme-ligand signature. It also has heme and NADPH binding sites homologous to previously described catalases. Pairwise alignment with its homologs revealed that LhCAT shares 95.1% identity with Oplegnathus fasciatus catalase and 97.4% similarity with Sparus aurata catalase. An uprooted phylogenetic tree demonstrated that LhCAT resides in a clade with catalases from other teleosts and exhibits a close relationship with Oplegnathus fasciatus catalase. Among twelve tissue types, we observed the highest LhCAT mRNA expression in the liver, followed by blood. Immune challenge by Lactococcus garvieae, or Poly I:C in the blood or spleen resulted in up-regulation at 24 h post injection. We also tested the antioxidant activity of recombinant LhCAT against hydrogen peroxide and found its optimal concentration to be 12.5 µg/mL. Collectively, these data suggested that LhCAT play an important role in antioxidant defense and immune response of red-lip mullet.


Assuntos
Catalase/metabolismo , Proteínas de Peixes/metabolismo , Smegmamorpha , Adjuvantes Imunológicos , Animais , Antioxidantes/metabolismo , Catalase/genética , DNA Complementar/genética , Proteínas de Peixes/genética , Perfilação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Heme/química , Peróxido de Hidrogênio/química , Sistema Imunitário , Ligantes , Fígado/enzimologia , Estresse Oxidativo , Filogenia , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Regulação para Cima
6.
Nat Commun ; 10(1): 2775, 2019 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-31235796

RESUMO

The recent development of chemical and bio-conjugation techniques allows for the engineering of various protein polymers. However, most of the polymerization process is difficult to control. To meet this challenge, we develop an enzymatic procedure to build polyprotein using the combination of a strict protein ligase OaAEP1 (Oldenlandia affinis asparaginyl endopeptidases 1) and a protease TEV (tobacco etch virus). We firstly demonstrate the use of OaAEP1-alone to build a sequence-uncontrolled ubiquitin polyprotein and covalently immobilize the coupled protein on the surface. Then, we construct a poly-metalloprotein, rubredoxin, from the purified monomer. Lastly, we show the feasibility of synthesizing protein polymers with rationally-controlled sequences by the synergy of the ligase and protease, which are verified by protein unfolding using atomic force microscopy-based single-molecule force spectroscopy (AFM-SMFS). Thus, this study provides a strategy for polyprotein engineering and immobilization.


Assuntos
Biocatálise , Endopeptidases/metabolismo , Proteínas de Plantas/metabolismo , Poliproteínas/síntese química , Engenharia de Proteínas/métodos , Estudos de Viabilidade , Microscopia de Força Atômica/métodos , Oldenlandia , Poliproteínas/genética , Poliproteínas/isolamento & purificação , Poliproteínas/ultraestrutura , Potyvirus , Desdobramento de Proteína , Proteínas Recombinantes/síntese química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/ultraestrutura , Rubredoxinas/síntese química , Rubredoxinas/genética , Rubredoxinas/isolamento & purificação , Rubredoxinas/ultraestrutura , Imagem Individual de Molécula/métodos , Análise Espectral/métodos , Proteínas Virais
7.
Nat Commun ; 10(1): 2493, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31175300

RESUMO

Tauopathies are neurodegenerative diseases characterized by intracellular amyloid deposits of tau protein. Missense mutations in the tau gene (MAPT) correlate with aggregation propensity and cause dominantly inherited tauopathies, but their biophysical mechanism driving amyloid formation is poorly understood. Many disease-associated mutations localize within tau's repeat domain at inter-repeat interfaces proximal to amyloidogenic sequences, such as 306VQIVYK311. We use cross-linking mass spectrometry, recombinant protein and synthetic peptide systems, in silico modeling, and cell models to conclude that the aggregation-prone 306VQIVYK311 motif forms metastable compact structures with its upstream sequence that modulates aggregation propensity. We report that disease-associated mutations, isomerization of a critical proline, or alternative splicing are all sufficient to destabilize this local structure and trigger spontaneous aggregation. These findings provide a biophysical framework to explain the basis of early conformational changes that may underlie genetic and sporadic tau pathogenesis.


Assuntos
Agregação Patológica de Proteínas/genética , Tauopatias/genética , Proteínas tau/genética , Motivos de Aminoácidos/genética , Simulação por Computador , Células HEK293 , Humanos , Espectrometria de Massas , Microscopia Eletrônica de Transmissão , Mutação de Sentido Incorreto , Agregação Patológica de Proteínas/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Proteínas tau/metabolismo , Proteínas tau/ultraestrutura
8.
Food Chem ; 295: 311-319, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174763

RESUMO

A novel gene aga3027 from the genome of Flammeovirga sp. OC4, isolated from the deep sea, was screened and expressed in Escherichia coli BL21. This gene encoded the genetic information of a potential agarase that consists of 851 amino acids and belongs to 16 ß-agarase family of glycoside hydrolase. Purified recombinant Aga3027 demonstrated the maximum activity of agarase at 40 °C and pH 9.0, displaying excellent thermostability and pH-stability. The agarase retained more than 80% of its maximum activity after incubation at 30-40 °C for 48 h, or after incubation at pH 6.0-9.0 for 60 min, which indicated that this agarase was suitable for industrial applications. Silica gel chromatography was used to purify the hydrolysates of agar treated by agarase from the recombinant Aga3027. The hydrolysates were identified as neoagarotetraose and neoagarohexaose by thin layer chromatography and further confirmed by ion chromatography.


Assuntos
Ágar/química , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/metabolismo , Ágar/metabolismo , Bacteroidetes/enzimologia , Bacteroidetes/genética , Cromatografia em Camada Delgada , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Galactosídeos/metabolismo , Glicosídeo Hidrolases/genética , Concentração de Íons de Hidrogênio , Hidrólise , Oligossacarídeos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Temperatura Ambiente
9.
Dokl Biochem Biophys ; 485(1): 101-103, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31201624

RESUMO

In this paper, we present an approach to optimize the heterologous expression of the receptor tyrosine kinase IRR, which further simplifies the purification of the IRR from the medium and increases the final yield. The approach proposed by us can find application in the biotechnological production of other large-scale recombinant proteins produced for medical purposes.


Assuntos
Receptor de Insulina/biossíntese , Animais , Células CHO , Cricetinae , Cricetulus , Humanos , Domínios Proteicos , Receptor de Insulina/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
10.
Biochemistry (Mosc) ; 84(6): 627-636, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31238862

RESUMO

The cytokine TRAIL induces apoptosis in tumor cells of various origin without affecting normal cells. Clinical trials of TRAIL-receptor (DR4 and DR5) agonists (recombinant TRAIL or death receptors antibodies) have largely failed because most human tumors were resistant to them. Currently, a second generation of agents targeted at TRAIL-R with increased efficiency has been developed. To this end, we have developed DR5-B, a variant of TRAIL selectively interacting with DR5. We have developed a new efficient method for production of TRAIL and DR5-B using expression of these proteins in Escherichia coli strain SHuffle B. The proteins were isolated from the cytoplasmic fraction of cells and purified to a high degree of homogeneity using metal-affinity and ion-exchange chromatography. The protein yield was 211 and 173 mg from one liter of cell culture for DR5-B and TRAIL, respectively, which significantly exceeded the results obtained by other methods. DR5-B killed tumor cells of different origin more efficiently and rapidly compared with TRAIL. The resulting preparations can be used for the study of TRAIL signaling pathways and in preclinical and clinical trials as antitumor agents.


Assuntos
Receptores do Ligante Indutor de Apoptose Relacionado a TNF/biossíntese , Ligante Indutor de Apoptose Relacionado a TNF/biossíntese , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Cromatografia de Afinidade/métodos , Cromatografia por Troca Iônica/métodos , Ensaios de Seleção de Medicamentos Antitumorais , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Humanos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/isolamento & purificação , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Ligante Indutor de Apoptose Relacionado a TNF/genética , Ligante Indutor de Apoptose Relacionado a TNF/isolamento & purificação , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia
11.
Prep Biochem Biotechnol ; 49(8): 800-806, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31156029

RESUMO

In this study, azurin, a bacteriocin with anticancer property, was produced by food-grade Lactococcus lactis using the Nisin Controlled Gene Expression (NICE) System. In addition, the antibacterial and cytotoxic properties of recombinant azurin in the culture supernatant were also investigated. Azurin gene from Pseudomonas aeruginosa was cloned into the pNZ8149 vector and the resulting recombinant DNA was transformed into food grade L. lactis NZ3900. The expression of azurin protein was induced by the optimum concentration of nisin for 3 h. Inhibition zones for Escherichia coli and Bacillus cereus were observed at 5.0 and 10 mg/mL concentrations of lyophilized supernatants containing azurin, but no inhibition zone at azurin-free lyophilized supernatants. When HUVEC, HT29, HCT116, and MCF7 cell lines were treated with lyophilized culture supernatants with azurin or without azurin, cell viability decreased with increasing concentrations of the supernatant. Furthermore, the supernatants containing azurin showed more anti-proliferative effect than the azurin-free supernatants. This work provides a practicable method to produce recombinant azurin in the food grade L. lactis strain. As a result, the recombinant L. lactis strain, producing azurin, can be used in the investigation of food biopreservatives and in the development of a therapeutic probiotic.


Assuntos
Azurina/genética , Clonagem Molecular/métodos , Lactococcus lactis/genética , Pseudomonas aeruginosa/genética , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Azurina/farmacologia , Bacillus cereus/efeitos dos fármacos , Linhagem Celular , Escherichia coli/efeitos dos fármacos , Amplificação de Genes , Humanos , Plasmídeos/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Transformação Genética
12.
Prep Biochem Biotechnol ; 49(8): 822-829, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31156045

RESUMO

Therapeutic monoclonal antibodies (mAbs) have become the dominant products in biopharmaceutical industry. Mammalian cell expression systems including Chinese hamster ovary (CHO) cells are the most commonly used hosts for the production of complex recombinant proteins. However, development of stable, high producing CHO cell lines suffers from the low expression level and instability of the transgene. The increasing efforts in the development of novel therapeutic antibodies and the advent of biosimilars have revealed the necessity for the development of improved platforms for rapid production of products for initial characterization and testing. In line with this premise, vector design and engineering has been applied to improve the expression level and stability of the transgene. This study reports the application of an improved lentiviral vector system containing the human interferon-ß scaffold attachment region (IFN-SAR) for the development of antibody producing stable CHO cells. mAb expressing clones producing 1100 µg/L of IgG1 monoclonal antibody were isolated without extensive screening of a large number of clones. Our results here indicate the positive effects of IFN-SAR on stable mAb expression using lentiviral based expression vectors. We also observed that although IFN-SAR can improve light chain (LC) and heavy chain (HC) gene copy numbers in stable cell pools, mAb expression in single cell clones was not affected by the transgene copy number.


Assuntos
Anticorpos Monoclonais/genética , Clonagem Molecular/métodos , Vetores Genéticos/genética , Lentivirus/genética , Animais , Células CHO , Linhagem Celular , Cricetulus , Dosagem de Genes , Humanos , Proteínas Recombinantes/genética , Transdução Genética
13.
Food Chem ; 295: 563-568, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174796

RESUMO

Enzyme specificity and particularity is needed not only in enzymatic separation methods, but also in enzymatic determination methods for plant compound extraction. Stevioside, rubusoside, and rebaudioside A are natural sweet compounds from plants. These compounds have the same skeleton and only contain different side-chain glucosyl groups, making them difficult to separate. However, enzymes that target diterpenoid compounds and show specific activity for side-chain glucosyl groups are rare. Herein, we report the identification and characterization of an enzyme that can target both diterpenoid compounds and sophorose, namely, ß-glucosidase SPBGL1 from Sphingomonas elodea ATCC 31461. SPBGL1 displayed high specificity toward sophorose, and activity toward stevioside, but not rebaudioside A. The stevioside conversion rate was 98%. SPBGL1 also operated at high substrate concentrations, such as in 50% crude steviol glycoside extract. Glucose liberated from stevioside was easy to quantify using the glucose oxidase method, allowing the stevioside content to be determined.


Assuntos
Diterpenos de Caurano/metabolismo , Glucosídeos/metabolismo , Sphingomonas/enzimologia , beta-Glucosidase/metabolismo , Hidrólise , Extratos Vegetais/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , beta-Glucosidase/genética
14.
Nat Commun ; 10(1): 2636, 2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-31201318

RESUMO

The leading cause of cystic fibrosis (CF) is the deletion of phenylalanine 508 (F508del) in the first nucleotide-binding domain (NBD1) of the cystic fibrosis transmembrane conductance regulator (CFTR). The mutation affects the thermodynamic stability of the domain and the integrity of the interface between NBD1 and the transmembrane domain leading to its clearance by the quality control system. Here, we develop nanobodies targeting NBD1 of human CFTR and demonstrate their ability to stabilize both isolated NBD1 and full-length protein. Crystal structures of NBD1-nanobody complexes provide an atomic description of the epitopes and reveal the molecular basis for stabilization. Furthermore, our data uncover a conformation of CFTR, involving detachment of NBD1 from the transmembrane domain, which contrast with the compact assembly observed in cryo-EM structures. This unexpected interface rearrangement is likely to have major relevance for CF pathogenesis but also for the normal function of CFTR and other ABC proteins.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/genética , Modelos Moleculares , Cristalografia por Raios X , Regulador de Condutância Transmembrana em Fibrose Cística/isolamento & purificação , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Humanos , Dobramento de Proteína , Domínios e Motivos de Interação entre Proteínas/genética , Estabilidade Proteica , Estrutura Terciária de Proteína/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Deleção de Sequência , Anticorpos de Domínio Único/metabolismo
15.
Nat Commun ; 10(1): 2641, 2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-31201325

RESUMO

Epsilon toxin (Etx), a potent pore forming toxin (PFT) produced by Clostridium perfringens, is responsible for the pathogenesis of enterotoxaemia of ruminants and has been suggested to play a role in multiple sclerosis in humans. Etx is a member of the aerolysin family of ß-PFTs (aß-PFTs). While the Etx soluble monomer structure was solved in 2004, Etx pore structure has remained elusive due to the difficulty of isolating the pore complex. Here we show the cryo-electron microscopy structure of Etx pore assembled on the membrane of susceptible cells. The pore structure explains important mutant phenotypes and suggests that the double ß-barrel, a common feature of the aß-PFTs, may be an important structural element in driving efficient pore formation. These insights provide the framework for the development of novel therapeutics to prevent human and animal infections, and are relevant for nano-biotechnology applications.


Assuntos
Toxinas Bacterianas/química , Clostridium perfringens/ultraestrutura , Animais , Toxinas Bacterianas/genética , Toxinas Bacterianas/isolamento & purificação , Toxinas Bacterianas/metabolismo , Biotecnologia/métodos , Linhagem Celular , Infecções por Clostridium/microbiologia , Infecções por Clostridium/prevenção & controle , Clostridium perfringens/genética , Clostridium perfringens/metabolismo , Clostridium perfringens/patogenicidade , Microscopia Crioeletrônica , Cães , Enterotoxemia/microbiologia , Enterotoxemia/prevenção & controle , Modelos Moleculares , Mutagênese Sítio-Dirigida , Nanotecnologia/métodos , Conformação Proteica em Folha beta/genética , Multimerização Proteica/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo
16.
Nat Commun ; 10(1): 2693, 2019 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-31217419

RESUMO

The kinesin-3 KIF1C is a fast organelle transporter implicated in the transport of dense core vesicles in neurons and the delivery of integrins to cell adhesions. Here we report the mechanisms of autoinhibition and release that control the activity of KIF1C. We show that the microtubule binding surface of KIF1C motor domain interacts with its stalk and that these autoinhibitory interactions are released upon binding of protein tyrosine phosphatase PTPN21. The FERM domain of PTPN21 stimulates dense core vesicle transport in primary hippocampal neurons and rescues integrin trafficking in KIF1C-depleted cells. In vitro, human full-length KIF1C is a processive, plus-end directed motor. Its landing rate onto microtubules increases in the presence of either PTPN21 FERM domain or the cargo adapter Hook3 that binds the same region of KIF1C tail. This autoinhibition release mechanism allows cargo-activated transport and might enable motors to participate in bidirectional cargo transport without undertaking a tug-of-war.


Assuntos
Cinesina/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Animais , Transporte Biológico , Linhagem Celular , Vesículas Citoplasmáticas/metabolismo , Hipocampo/citologia , Humanos , Integrinas/metabolismo , Microscopia Intravital/métodos , Cinesina/genética , Cinesina/isolamento & purificação , Camundongos , Proteínas Associadas aos Microtúbulos/isolamento & purificação , Microtúbulos/metabolismo , Neurônios/citologia , Cultura Primária de Células , Ligação Proteica , Domínios Proteicos , Proteínas Tirosina Fosfatases não Receptoras/genética , Proteínas Tirosina Fosfatases não Receptoras/isolamento & purificação , RNA Interferente Pequeno/metabolismo , Ratos , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Imagem Individual de Molécula/métodos
17.
Cancer Immunol Immunother ; 68(7): 1143-1155, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31177328

RESUMO

Enhancement of endogenous immunity to tumor-associated self-antigens and neoantigens is the goal of preventive vaccination. Toward this goal, we compared the efficacy of the following HER2 DNA vaccine constructs: vaccines encoding wild-type HER2, hybrid HER2 vaccines consisting of human HER2 and rat Neu, HER2 vaccines with single residue substitutions and a novel human HER2 DNA vaccine, ph(es)E2TM. ph(es)E2TM was designed to contain five evolution-selected substitutions: M198V, Q398R, F425L, H473R and A622T that occur frequently in 12 primate HER2 sequences. These ph(es)E2TM substitutions score 0 to 1 in blocks substitutions matrix (BLOSUM), indicating minimal biochemical alterations. h(es)E2TM recombinant protein is recognized by a panel of anti-HER2 mAbs, demonstrating the preservation of HER2 protein structure. Compared to native human HER2, electrovaccination of HER2 transgenic mice with ph(es)E2TM induced a threefold increase in HER2-binding antibody (Ab) and elevated levels of IFNγ-producing T cells. ph(es)E2TM, but not pE2TM immune serum, recognized HER2 peptide p95 355LPESFDGDPASNTAP369, suggesting a broadening of epitope recognition induced by the minimally modified HER2 vaccine. ph(es)E2TM vaccination reduced tumor growth more effectively than wild-type HER2 or HER2 vaccines with more extensive modifications. The elevation of tumor immunity by ph(es)E2TM vaccination would create a favorable tumor microenvironment for neoantigen priming, further enhancing the protective immunity. The fundamental principle of exploiting evolution-selected amino acid substitutions is novel, effective and applicable to vaccine development in general.


Assuntos
Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/imunologia , Imunoterapia/métodos , Neoplasias Mamárias Experimentais/terapia , Receptor ErbB-2/imunologia , Substituição de Aminoácidos/genética , Substituição de Aminoácidos/imunologia , Animais , Antígenos de Neoplasias/genética , Vacinas Anticâncer/genética , Vacinas Anticâncer/uso terapêutico , Linhagem Celular Tumoral/transplante , Células Dendríticas/imunologia , Evolução Molecular , Feminino , Imunogenicidade da Vacina/genética , Neoplasias Mamárias Experimentais/genética , Neoplasias Mamárias Experimentais/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Receptor ErbB-2/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Tolerância a Antígenos Próprios/genética , Microambiente Tumoral/imunologia , Vacinas de DNA/genética , Vacinas de DNA/imunologia , Vacinas de DNA/uso terapêutico
18.
Nat Commun ; 10(1): 2747, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227715

RESUMO

Many intracellular bacteria, including Chlamydia, establish a parasitic membrane-bound organelle inside the host cell that is essential for the bacteria's survival. Chlamydia trachomatis forms inclusions that are decorated with poorly characterized membrane proteins known as Incs. The prototypical Inc, called IncA, enhances Chlamydia pathogenicity by promoting the homotypic fusion of inclusions and shares structural and functional similarity to eukaryotic SNAREs. Here, we present the atomic structure of the cytoplasmic domain of IncA, which reveals a non-canonical four-helix bundle. Structure-based mutagenesis, molecular dynamics simulation, and functional cellular assays identify an intramolecular clamp that is essential for IncA-mediated homotypic membrane fusion during infection.


Assuntos
Proteínas de Bactérias/ultraestrutura , Infecções por Chlamydia/microbiologia , Chlamydia trachomatis/patogenicidade , Corpos de Inclusão/microbiologia , Fusão de Membrana , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Chlamydia trachomatis/genética , Chlamydia trachomatis/metabolismo , Cristalografia por Raios X , Técnicas de Inativação de Genes , Células HeLa , Humanos , Simulação de Dinâmica Molecular , Mutagênese , Conformação Proteica em alfa-Hélice , Domínios Proteicos/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura , Proteínas SNARE/química
19.
Parasitol Int ; 72: 101938, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31201923

RESUMO

Plasmodium falciparum is a blood protozoan parasite, transmitted by Anopheles mosquitoes vectors, that can cause morbidity and even leads to mortality in tropical countries. Strategies are directed to combat malaria including development of diagnostic tools, serological markers and vaccinations. A target under intensive studies is Merozoite Surface Protein (MSP)-3. The aim of this study is to express and purify recombinant MSP3 of P. falciparum (rPfMSP3) using silkworm expression system as a host for its large-scale production and to investigate its potential effectiveness for sero-diagnosis. The rPfMSP3 formed oligomers in a blue-native PAGE and its N-glycosylation was confirmed by periodic acid-Schiff staining and PNGase F treatment. The amyloid-like morphology of the rPfMSP3 oligomers was observed. Enzyme-linked immunosorbent assay showed that 60-70% of human samples from subjects living in malaria endemic areas in Indonesia detected the rPfMSP3. Western blot results showed that the rPfMSP3 was recognized by a malaria infected human serum but not by an uninfected human serum. The rPfMSP3 was successfully expressed in silkworm as a soluble protein and has the potential to be used in serological measurement for detecting PfMSP3-specific antibodies in sera from individuals living in endemic areas.


Assuntos
Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Malária Falciparum/diagnóstico , Proteínas de Protozoários/imunologia , Animais , Antígenos de Protozoários/genética , Bombyx/genética , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina G/sangue , Malária Falciparum/imunologia , Proteínas de Membrana/genética , Proteínas de Membrana/imunologia , Merozoítos/imunologia , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Testes Sorológicos
20.
Nat Commun ; 10(1): 2685, 2019 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-31213605

RESUMO

Hypertrophic cardiomyopathy (HCM) affects 1 in 500 people and leads to hyper-contractility of the heart. Nearly 40 percent of HCM-causing mutations are found in human ß-cardiac myosin. Previous studies looking at the effect of HCM mutations on the force, velocity and ATPase activity of the catalytic domain of human ß-cardiac myosin have not shown clear trends leading to hypercontractility at the molecular scale. Here we present functional data showing that four separate HCM mutations located at the myosin head-tail (R249Q, H251N) and head-head (D382Y, R719W) interfaces of a folded-back sequestered state referred to as the interacting heads motif (IHM) lead to a significant increase in the number of heads functionally accessible for interaction with actin. These results provide evidence that HCM mutations can modulate myosin activity by disrupting intramolecular interactions within the proposed sequestered state, which could lead to hypercontractility at the molecular level.


Assuntos
Miosinas Cardíacas/metabolismo , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/fisiopatologia , Contração Miocárdica/genética , Cadeias Pesadas de Miosina/metabolismo , Actinas/metabolismo , Animais , Miosinas Cardíacas/genética , Linhagem Celular , Movimento Celular/genética , Coração/fisiopatologia , Humanos , Camundongos , Mutação , Mioblastos , Cadeias Pesadas de Miosina/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
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