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1.
Purinergic Signal ; 2023 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-37999896

RESUMEN

Leishmania braziliensis is a pathogenic protozoan parasite that causes American Tegumentary Leishmaniasis (ATL), an important tropical neglected disease. ENTPDases are nucleotidases that hydrolyze intracellular and/or extracellular nucleotides. ENTPDases are known as regulators of purinergic signalling induced by extracellular nucleotides. Leishmania species have two isoforms of ENTPDase, and, particularly, ENTPDase2 seems to be involved in infectivity and virulence. In this study, we conducted the heterologous expression and biochemical characterization of the recombinant ENTPDase2 of L. braziliensis (rLbNTPDase2). Our results show that this enzyme is a canonical ENTPDase with apyrase activity, capable of hydrolysing triphosphate and diphosphate nucleotides, and it is dependent on divalent cations (calcium or magnesium). Substrate specificity was characterized as UDP>GDP>ADP>GTP>ATP=UTP. The enzyme showed optimal activity at a neutral to basic pH and was partially inhibited by suramin and DIDS. Furthermore, the low apparent Km for ADP suggests that the enzyme may play a role in adenosine-mediated signalling. The biochemical characterization of this enzyme can open new avenues for using LbNTPDase2 as a drug target.

2.
Braz J Microbiol ; 54(4): 2755-2763, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37880563

RESUMEN

Escherichia coli cells rapidly respond to changes in the environment. Such response must be anticipated upon development of fermentation strategy for commercial purposes. The response may signal changes in cell physiology, which is critical for the cell growth and the level of the target protein production. One of the responses is the elevated expression of membrane proteins to tightly control the trafficking of molecules into and out from the cells. Normally, the expression level of the membrane protein is basal as the fermentation is carried out in physiological conditions. Here, we reported an elevated expression of the outer membrane protein A (OmpA) during a series of fermentation conduct, starting from the shake flask, 1-L to finally 10-L fermentor. The incidence led to a lower expression of the target protein and thereby resulting in lower process efficiency. OmpA expression was concomitant to the bacterial growth and already observed in the early exponential phase. Despite the drawback, this phenomenon actually inspires the observation of OmpA expression as one of the indicators for the E. coli cells response to the fermentation conditions. This auxiliary check would prevent the higher OmpA expression that led to the low expression of the target protein.


Asunto(s)
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/metabolismo , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo
3.
Vaccines (Basel) ; 11(10)2023 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-37896924

RESUMEN

Influenza virus infections represent an ongoing public health threat as well as an economic burden. Although seasonal influenza vaccines have been available for some decades, efforts are being made to generate new efficient, flexible, and cost-effective technologies to be transferred into production. Our work describes the development of a model influenza hemagglutinin antigen that is capable of inducing protection against viral challenge in mice. High amounts of the H1 hemagglutinin ectodomain, HA18-528, were expressed in a bacterial system as insoluble inclusion bodies. Solubilization was followed by a thorough differential scanning fluorimetry (DSF)-guided optimization of refolding, which allows for fast and reliable screening of several refolding conditions, yielding tens of milligrams/L of folded protein. Structural and functional analysis revealed native-like folding as well as the presence of a mix of monomers and oligomers in solution. Mice immunized with HA18-528 were protected when exposed to influenza A virus as opposed to mice that received full-length denatured protein. Sera of mice immunized with HA18-528 showed both high titers of antigen-specific IgG1 and IgG2a isotypes as well as viral neutralization activity. These results prove the feasibility of the recombinant bacterial expression system coupled with DSF-guided refolding in providing influenza hemagglutinin for vaccine development.

4.
Protein Expr Purif ; 192: 106041, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34953978

RESUMEN

The gene encoding the cAMP-dependent protein kinase (PKA) catalytic subunit-like protein PKAC1 from the Venezuelan TeAp-N/D1 strain of Trypanosoma equiperdum was cloned, and the recombinant TeqPKAC1 protein was overexpressed in bacteria. A major polypeptide with an apparent molecular mass of ∼38 kDa was detected by SDS-polyacrylamide gel electrophoresis, and immunoblotting using antibodies against the human PKA catalytic subunit α. Unfortunately, most of the expressed TeqPKAC1 was highly insoluble. Polypeptides of 36-38 kDa and 45-50 kDa were predominantly seen by immunoblotting in the bacterial particulate and cytosolic fractions, respectively. Since the incorporation of either 4% Triton X-100 or 3% sarkosyl or a mixture of 10 mM MgCl2 and 1 mM ATP (MgATP) improved the solubilization of TeqPKAC1, we used a combination of Triton X-100, sarkosyl and MgATP to solubilize the recombinant protein. TeqPKAC1 was purified by first reconstituting a hybrid holoenzyme between the recombinant protein and a mammalian poly-His-tagged PKA regulatory subunit that was immobilized on a Ni2+-chelating affinity resin, and then by eluting TeqPKAC1 using cAMP. TeqPKAC1 was functional given that it was capable of phosphorylating PKA catalytic subunit substrates, such as kemptide (LRRASLG), histone type II-AS, and the peptide SP20 (TTYADFIASGRTGRRNSIHD), and was inhibited by the peptide IP20 (TTYADFIASGRTGRRNAIHD), which contains the inhibitory motif of the PKA-specific heat-stable inhibitor PKI-α. Optimal enzymatic activity was obtained at 37 °C and pH 8.0-9.0; and the order of effectiveness of nucleotide triphosphates and divalent cations was ATP ¼ GTP â‰… ITP and Mg2+ â‰… Mn2+ â‰… Fe2+ ¼ Ca2+ â‰… Zn2, respectively.


Asunto(s)
Clonación Molecular , Proteínas Quinasas Dependientes de AMP Cíclico/genética , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , Trypanosoma/enzimología , AMP Cíclico/genética , Proteínas Quinasas Dependientes de AMP Cíclico/química , Proteínas Quinasas Dependientes de AMP Cíclico/aislamiento & purificación , Fosforilación , Subunidades de Proteína/química , Subunidades de Proteína/genética , Subunidades de Proteína/aislamiento & purificación , Subunidades de Proteína/metabolismo , Proteínas Protozoarias/química , Proteínas Protozoarias/aislamiento & purificación , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Solubilidad , Trypanosoma/química , Trypanosoma/genética
5.
Electron. j. biotechnol ; Electron. j. biotechnol;54: 26-36, nov.2021. ilus, graf
Artículo en Inglés | LILACS | ID: biblio-1510830

RESUMEN

BACKGROUND The heterologous expression of parasitic proteins is challenging because the sequence composition often differs significantly from host preferences. However, the production of such proteins is important because they are potential drug targets and can be screened for interactions with new lead compounds. Here we compared two expression systems for the production of an active recombinant aldehyde dehydrogenase (SmALDH_312) from Schistosoma mansoni, which causes the neglected tropical disease schistosomiasis. RESULTS We produced SmALDH_312 successfully in the bacterium Escherichia coli and in the baculovirus expression vector system (BEVS). Both versions of the recombinant protein were found to be active in vitro, but the BEVS-derived enzyme showed 3.7-fold higher specific activity and was selected for further characterization. We investigated the influence of Mg2+, Ca2+ and Mn2+, and found out that the specific activity of the enzyme increased 1.5-fold in the presence of 0.5 mM Mg2+. Finally, we characterized the kinetic properties of the enzyme using a design-of-experiment approach, revealing optimal activity at pH 7.6 and 41C. CONCLUSIONS Although, E. coli has many advantages, such as rapid expression, high yields and low costs, this system was outperformed by BEVS for the production of a schistosome ALDH. BEVS therefore rovides an opportunity for the expression and subsequent evaluation of schistosome enzymes as drug targets


Asunto(s)
Baculoviridae/enzimología , Escherichia coli/enzimología , Esquistosomiasis/tratamiento farmacológico , Cinética , Proteínas/farmacocinética , Baculoviridae/química , Escherichia coli/química
6.
Protein Sci ; 28(4): 800-807, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30653276

RESUMEN

The production of recombinant proteins in bacteria has increased significantly in recent years, becoming a common tool for both research and the industrial production of proteins. One of the requirements of this methodology is to obtain the desired protein without contaminants. However, this goal cannot always be readily achieved. Multiple strategies have been developed to improve the quality of the desired protein product. Nevertheless, contamination with molecular chaperones is one of the recalcitrant problems that still affects the quality of the obtained proteins. The ability of chaperones to bind to unfolded proteins or to regions where the polypeptide chain is exposed make the removal of the contamination during purification challenging to achieve. This work aimed to develop a strategy to remove contaminating DnaK, one of the homologous Hsp70 molecular chaperones found in Escherichia coli, from purified recombinant proteins. For this purpose, we developed a methodology that captures the DnaK from the contaminating proteins by co-incubation with a GST-cleanser protein that has free functional binding sites for the chaperone. The cleanser protein can then be easily removed together with the captured DnaK. Here, we demonstrated the utility of our system by decontaminating a Histidine-tagged recombinant protein in a batch process. The addition of the GST-cleanser protein in the presence of ATP-Mg eliminates the DnaK contamination substantially. Thus, our decontaminant strategy results versatile and straightforward and can be applied to proteins obtained with different expression and purifications systems as well as to small samples or large volume preparations.


Asunto(s)
Proteínas de Escherichia coli/aislamiento & purificación , Escherichia coli/química , Proteínas HSP70 de Choque Térmico/aislamiento & purificación , Proteínas Recombinantes/química , Sitios de Unión , Western Blotting , Electroforesis en Gel de Poliacrilamida , Proteínas Inmovilizadas/química
7.
Microb Cell Fact ; 16(1): 196, 2017 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-29132366

RESUMEN

BACKGROUND: In the present work we described the recombinant production and characterization of heterodimeric construction ZnT8-Arg-Trp325 fused to thioredoxin using a high-performance expression system such as Escherichia coli. In addition, we apply this novel recombinant antigen in a non-radiometric method, with high sensitivity, low operational complexity and lower costs. RESULTS: ZnT8 was expressed in E. coli as a fusion protein with thioredoxin (TrxZnT8). After 3 h for induction, recombinant protein was obtained from the intracellular soluble fraction and from inclusion bodies and purified by affinity chromatography. The expression and purification steps, analyzed by SDS-PAGE and western blot, revealed a band compatible with TrxZnT8 expected theoretical molecular weight (≈ 36.8 kDa). The immunochemical ability of TrxZnT8 to compete with [35S]ZnT8 (synthesized with rabbit reticulocyte lysate system) was assessed qualitatively by incubating ZnT8A positive patient sera in the presence of 0.2-0.3 µM TrxZnT8. Results were expressed as standard deviation scores (SDs). All sera became virtually negative under antigen excess (19.26-1.29 for TrxZnT8). Also, radiometric quantitative competition assays with ZnT8A positive patient sera were performed by adding TrxZnT8 (37.0 pM-2.2 µM), using [35S]ZnT8. All dose-response curves showed similar protein concentration that caused 50% inhibition (14.9-0.15 nM for TrxZnT8). On the other hand, preincubated bridge ELISA for ZnT8A detection was developed. This assay showed 51.7% of sensitivity and 97.1% of specificity. CONCLUSIONS: It was possible to obtain with high-yield purified heterodimeric construction of ZnT8 in E. coli and it was applied in cost-effective immunoassay for ZnT8A detection.


Asunto(s)
Autoanticuerpos/sangre , Diabetes Mellitus Tipo 1/inmunología , Escherichia coli/genética , Transportador 8 de Zinc/genética , Transportador 8 de Zinc/inmunología , Animales , Antígenos/genética , Antígenos/inmunología , Autoanticuerpos/inmunología , Ensayo de Inmunoadsorción Enzimática/economía , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Conejos , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/aislamiento & purificación , Tiorredoxinas/química , Tiorredoxinas/genética
8.
Free Radic Biol Med ; 112: 524-533, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28865997

RESUMEN

To combat the deleterious effects that oxidation of the sulfur atom in methionine to sulfoxide may bring, aerobic cells express repair pathways involving methionine sulfoxide reductases (MSRs) to reverse the above reaction. Here, we show that Trypanosoma brucei, the causative agent of African trypanosomiasis, expresses two distinct trypanothione-dependent MSRs that can be distinguished from each other based on sequence, sub-cellular localisation and substrate preference. One enzyme found in the parasite's cytosol, shows homology to the MSRA family of repair proteins and preferentially metabolises the S epimer of methionine sulfoxide. The second, which contains sequence motifs present in MSRBs, is restricted to the mitochondrion and can only catalyse reduction of the R form of peptide-bound methionine sulfoxide. The importance of these proteins to the parasite was demonstrated using functional genomic-based approaches to produce cells with reduced or elevated expression levels of MSRA, which exhibited altered susceptibility to exogenous H2O2. These findings identify new reparative pathways that function to fix oxidatively damaged methionine within this medically important parasite.


Asunto(s)
Metionina Sulfóxido Reductasas/genética , Metionina/análogos & derivados , Metionina/metabolismo , Proteínas Protozoarias/genética , Trypanosoma brucei brucei/genética , Secuencia de Aminoácidos , Biocatálisis , Citosol/efectos de los fármacos , Citosol/enzimología , Expresión Génica , Prueba de Complementación Genética , Peróxido de Hidrógeno/metabolismo , Peróxido de Hidrógeno/farmacología , Isoenzimas/genética , Isoenzimas/metabolismo , Metionina Sulfóxido Reductasas/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/enzimología , Oxidación-Reducción , Proteínas Protozoarias/metabolismo , Saccharomyces cerevisiae/enzimología , Saccharomyces cerevisiae/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Estereoisomerismo , Especificidad por Sustrato , Trypanosoma brucei brucei/efectos de los fármacos , Trypanosoma brucei brucei/enzimología
9.
Biochem Biophys Res Commun ; 487(1): 28-33, 2017 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-28365155

RESUMEN

Human Leucocyte Antigen-G (HLA-G) is a non classical major histocompatibility complex (MHC) molecule that through RNA splicing can encode seven isoforms which are membrane bound (-G1, -G2, -G3 and -G4) and soluble (-G5, -G6 and -G7). HLA-G is described as important immune suppressor endogenous molecule to favor maternal-fetal tolerance, transplant survival and tumor immune scape. HLA-G shows low protein variability and a unique structural complexity that is related with the expression of different isoforms followed by biochemical processes, such as, proteolytic cleavage, molecular interactions, and protein ubiquitination. Studies with HLA-G have shown difficult to assess the role of the individual isoforms. Thus, the aim of this work was to obtain a HLA-G6 recombinant form. The results indicated the production of high homogeneous preparations of soluble recombinant HLA-G6 (srHLA-G6) with molecular mass 23,603.76 Da, determined by MALD-TOF/TOF. In addition, native and denatured srHLA-G6 were detected by ELISA, using commercial monoclonal antibodies. Finally, we developed a suitable methodology to express srHLA-G6 that could contribute in structural and functional studies involving specific isoforms.


Asunto(s)
Antígenos HLA-G/química , Antígenos HLA-G/inmunología , Proteínas Recombinantes/química , Sitios de Unión , Humanos , Peso Molecular , Unión Proteica , Solubilidad
10.
BMC Biotechnol ; 16(1): 84, 2016 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-27881117

RESUMEN

BACKGROUND: The insulinoma associated protein tyrosine phosphatase 2 (IA-2) is one of the immunodominant autoantigens involved in the autoimmune attack to the beta-cell in Type 1 Diabetes Mellitus. In this work we have developed a complete and original process for the production and recovery of the properly folded intracellular domain of IA-2 fused to thioredoxin (TrxIA-2ic) in Escherichia coli GI698 and GI724 strains. We have also carried out the biochemical and immunochemical characterization of TrxIA-2icand design variants of non-radiometric immunoassays for the efficient detection of IA-2 autoantibodies (IA-2A). RESULTS: The main findings can be summarized in the following statements: i) TrxIA-2ic expression after 3 h of induction on GI724 strain yielded ≈ 10 mg of highly pure TrxIA-2ic/L of culture medium by a single step purification by affinity chromatography, ii) the molecular weight of TrxIA-2ic (55,358 Da) could be estimated by SDS-PAGE, size exclusion chromatography and mass spectrometry, iii) TrxIA-2ic was properly identified by western blot and mass spectrometric analysis of proteolytic digestions (63.25 % total coverage), iv) excellent immunochemical behavior of properly folded full TrxIA-2ic was legitimized by inhibition or displacement of [35S]IA-2 binding from IA-2A present in Argentinian Type 1 Diabetic patients, v) great stability over time was found under proper storage conditions and vi) low cost and environmentally harmless ELISA methods for IA-2A assessment were developed, with colorimetric or chemiluminescent detection. CONCLUSIONS: E. coli GI724 strain emerged as a handy source of recombinant IA-2ic, achieving high levels of expression as a thioredoxin fusion protein, adequately validated and applicable to the development of innovative and cost-effective immunoassays for IA-2A detection in most laboratories.


Asunto(s)
Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/inmunología , Escherichia coli/metabolismo , Ingeniería de Proteínas/métodos , Proteínas Tirosina Fosfatasas Clase 8 Similares a Receptores/inmunología , Tiorredoxinas/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Diabetes Mellitus Tipo 1/sangre , Escherichia coli/genética , Femenino , Humanos , Pruebas Inmunológicas/métodos , Masculino , Persona de Mediana Edad , Proteínas Tirosina Fosfatasas Clase 8 Similares a Receptores/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/inmunología , Tiorredoxinas/genética , Adulto Joven
11.
Amino Acids ; 48(9): 2205-14, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27209197

RESUMEN

Snake venom metalloproteinases (SVMPs) participate in snakebite pathology such as hemorrhage, inflammation, and necrosis. They are synthesized as latent multi-domain precursors whose processing generates either catalytically active enzymes or free non-enzymatic domains. Recombinant expression of the precursor of P-III class SVMPs has failed due to the instability of the multi-domain polypeptide structure. Conversely, functional recombinant non-catalytic domains were obtained by prokaryotic expression systems. Here, we show for the first time the recombinant expression of the precursor of HF3, a highly hemorrhagic SVMP from Bothrops jararaca, and its non-catalytic domains, using an E. coli-based cell-free synthesis system. The precursor of HF3, composed of pro-, metalloproteinase-, disintegrin-like-, and cysteine-rich domains, and containing 38 Cys residues, was successfully expressed and purified. A protein composed of the disintegrin-like and cysteine-rich domains (DC protein) and the cysteine-rich domain alone (C protein) were expressed in vitro individually and purified. Both proteins were shown to be functional in assays monitoring the interaction with matrix proteins and in modulating the cleavage of fibrinogen by HF3. These data indicate that recombinant expression using prokaryotic-based cell-free synthesis emerges as an attractive alternative for the study of the structure and function of multi-domain proteins with a high content of Cys residues.


Asunto(s)
Bothrops , Venenos de Crotálidos/biosíntesis , Venenos de Crotálidos/química , Expresión Génica , Metaloproteasas/biosíntesis , Metaloproteasas/química , Animales , Sistema Libre de Células/química , Sistema Libre de Células/metabolismo , Venenos de Crotálidos/genética , Metaloproteasas/genética , Dominios Proteicos , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/genética
12.
Electron. j. biotechnol ; Electron. j. biotechnol;19(3): 1-9, May 2016. ilus
Artículo en Inglés | LILACS | ID: lil-787003

RESUMEN

Background: Human is an essential cellular enzyme that is found in all human cells. As this enzyme is upregulated in cancer cells exceedingly, it is used as a target for cancer chemotherapeutic drug development. As such, producing the in-house enzyme for the purpose to speed up the search for more cost-effective and target specific hTopoI inhibitors is warranted. This study aims to compare the optimised conditions for the expression of hTopoI in KM71H (MutS) and X33 (Mut+) strains of Pichia pastoris. P. pastoris transfected with an hTopoI recombinant vector was used for the optimization of a higher level of hTopoI expression. Results: In the process, fed-batch cultivation parameters that influence the expression of hTopoI, such as culture temperature, methanol induction and feeding strategy, were optimised in the transfected KM71H and X33 P. pastoris strains in a shake flask system. The cell density and total protein concentration (protein level) of transfected P. pastoris were compared to determine the optimum culture conditions for each transfected P. pastoris strain. A higher hTopoI level was observed in the transfected KM71H culture supernatant (2.26 ng/mL) when the culture was incubated in the optimum conditions. Conclusions: This study demonstrated that MutS strain (KM71H) expressed and secreted a higher level of hTopoI heterologous protein in the presence of methanol compared to the Mut+ strain; X33 (0.75 ng/mL). However, other aspects of optimization, such as pH, should also be considered in the future, to obtain the optimum expression level of hTopoI in P. pastoris.


Asunto(s)
Pichia , Proteínas Recombinantes , ADN-Topoisomerasas de Tipo I , Técnicas de Cultivo , Concentración de Iones de Hidrógeno
13.
Biomol NMR Assign ; 9(2): 247-51, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25291978

RESUMEN

Macro domains consist of 130-190 amino acid residues and appear to be highly conserved in all kingdoms of life. Intense research on this field has shown that macro domains bind ADP-ribose and other similar molecules, but their exact function still remains intangible. Macro domains are highly conserved in the Alphavirus genus and the Venezuelan equine encephalitis virus (VEEV) is a member of this genus that causes fatal encephalitis to equines and humans. In this study we report the high yield recombinant expression and preliminary solution NMR study of the macro domain of VEEV. An almost complete sequence-specific assignment of its (1)H, (15)N and (13)C resonances was obtained and its secondary structure predicted by TALOS+. The protein shows a unique mixed α/ß-fold.


Asunto(s)
Espectroscopía de Resonancia Magnética con Carbono-13 , Virus de la Encefalitis Equina Venezolana/metabolismo , Resonancia Magnética Nuclear Biomolecular , Espectroscopía de Protones por Resonancia Magnética , Proteínas no Estructurales Virales/química , Secuencia de Aminoácidos , Datos de Secuencia Molecular , Isótopos de Nitrógeno , Estructura Terciaria de Proteína , Alineación de Secuencia
14.
Front Microbiol ; 5: 172, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24860555

RESUMEN

Escherichia coli is one of the organisms of choice for the production of recombinant proteins. Its use as a cell factory is well-established and it has become the most popular expression platform. For this reason, there are many molecular tools and protocols at hand for the high-level production of heterologous proteins, such as a vast catalog of expression plasmids, a great number of engineered strains and many cultivation strategies. We review the different approaches for the synthesis of recombinant proteins in E. coli and discuss recent progress in this ever-growing field.

15.
Front Microbiol ; 5: 56, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24592259

RESUMEN

The formation of inclusion bodies (IBs) constitute a frequent event during the production of heterologous proteins in bacterial hosts. Although the mechanisms leading to their formation are not completely understood, empirical data have been exploited trying to predict the aggregation propensity of specific proteins while a great number of strategies have been developed to avoid the generation of IBs. However, in many cases, the formation of such aggregates can be considered an advantage for basic research as for protein production. In this review, we focus on this positive side of IBs formation in bacteria. We present a compilation on recent advances on the understanding of IBs formation and their utilization as a model to understand protein aggregation and to explore strategies to control this process. We include recent information about their composition and structure, their use as an attractive approach to produce low cost proteins and other promising applications in Biomedicine.

16.
São Paulo; s.n; 2008. 143 p. ilus, tab, graf.
Tesis en Portugués | LILACS | ID: lil-566893

RESUMEN

As BMPs (Bone Morphogenetic Proteins) são membros da superfamília de proteínas TGF-β (Transforming Growth Factor β ), regulam o crescimento e diferenciação de vários tipos celulares em diversos tecidos, e algumas delas desempenham um papel crítico na diferenciação de células de origem mesenquimal em osteoblastos. Particularmente, rhBMP2 e rhBMP7, promovem osteoindução tanto /"in vitro/" como /"in vivo,/" sendo, ambas as proteínas utilizadas terapeuticamente em Ortopedia/Odontologia para reparo ósseo. A expressão diferencial de genes durante a osteodiferenciação de células C2C12 induzida por rhBMP2 e rhBMP7, foi analisada através de microarranjos de DNA, selecionando 31 genes, dos quais 24 foram validados por qPCR, 13 dos quais são relacionados à transcrição, quatro associados a algumas vias de sinalização celular e sete associados à matriz extracelular. Análise funcional destes genes permitirá conhecer, com maiores detalhes, os eventos moleculares que ocorrem durante a diferenciação osteoblástica de células C2C12 induzida por rhBMPs. Em paralelo, foi perseguida a super-expressão de rhBMP2 e rhBMP7 em células HEK293T, demonstrando-se a atividade de rhBMP7, induzindo osteodiferenciação /"in vitro/" e formação de osso /"in vivo/", demonstrando a viabilidade do objetivo de se produzir estas proteínas para futura aplicação como biofármacos no Brasil.


The BMPs (Bone Morphogenetic Proteins) are members of the TGF-β (Transforming Growth Factor β) superfamily of proteins, regulate growth and differentiation of various cell types in various tissues, and some play a critical role in differentiation of mesenchymal cells into osteoblasts. Particularly, rhBMP2 and rhBMP7, promote osteoinduction /"in vitro/" and /"in vivo/" and both proteins are used therapeutically in Orthopedics and Dentistry. The differential expression of genes during osteodifferentiation induced by rhBMP2 and rhBMP7 in C2C12 cells was analyzed through DNA microarrays, allowing the selection of 31 genes, of which 24 were validated by qPCR, 13 of which are related to transcription, four associated with cell signaling pathways and seven are associated with the extracellular matrix. Subsequent functional analysis of these genes should reveal more details on the molecular events which take place during C2C12 cells osteoblastic differentiation induced by rhBMPs In paralel, rhBMPs 2 and 7 were overexpressed in HEK293T cells and BMP7 activity to induce osteodifferentiation /"in vitro/" and bone formation /"in vivo/" was demonstrated, reinforcing the viability of our objective to produce these proteins for future application as biopharmaceuticals in Brazil


Asunto(s)
Animales , Proteínas Morfogenéticas Óseas , Diferenciación Celular , Expresión Génica , Genes , Mamíferos , Osteogénesis , Mantenimiento Correctivo/análisis , Osteoblastos , Proteínas Recombinantes
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