81 research outputs found

    The pURI family of expression vectors: A versatile set of ligation independent cloning plasmids for producing recombinant His-fusion proteins

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    A family of restriction enzyme- and ligation-independent cloning vectors has been developed for producing recombinant His-tagged fusion proteins in Escherichia coli. These are based on pURI2 and pURI3 expression vectors which have been previously used for the successful production of recombinant proteins at the milligram scale. The newly designed vectors combines two different promoters (lppp-5 and T7 RNA polymerase Ø10), two different endoprotease recognition sites for the His6-tag removal (enterokinase and tobacco etch virus), different antibiotic selectable markers (ampicillin and erythromycin resistance), and different placements of the His 6-tag (N- and C-terminus). A single gene can be cloned and further expressed in the eight pURI vectors by using six nucleotide primers, avoiding the restriction enzyme and ligation steps. A unique NotI site was introduced to facilitate the selection of the recombinant plasmid. As a case study, the new vectors have been used to clone the gene coding for the phenolic acid decarboxylase from Lactobacillus plantarum. Interestingly, the obtained results revealed markedly different production levels of the target protein, emphasizing the relevance of the cloning strategy on soluble protein production yield. Efficient purification and tag removal steps showed that the affinity tag and the protease cleavage sites functioned properly. The novel family of pURI vectors designed for parallel cloning is a useful and versatile tool for the production and purification of a protein of interest. © 2010 Elsevier Inc. All rights reserved.This work was supported by grants RM2008-00002 (Instituto Nacional de Investigación Agraria y Alimentaría), AGL2008-01052, Consolider INGENIO 2010 CSD2007-00063 FUN-C-FOOD (Comisión Interministerial de Ciencia y Tecnología), and S-0505/AGR/000153 and S2009/AGR-1469 (ALIBIRD) (Comunidad de Madrid). J.M.M. thanks the Ministerio de Ciencia e Innovación for a research grant (BFU2007-67404/BMC) and “Factoría de Cristalización” Consolider-Ingenio 2010 in support of his research. The technical assistance of M.V. Santamaría is greatly appreciated. J.A. Curiel is a recipient of a predoctoral fellowship from the MEC.Peer Reviewe

    The Lp_3561 and Lp_3562 enzymes support a functional divergence process in the lipase/esterase toolkit from Lactobacillus plantarum

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    Lactobacillus plantarum species is a good source of esterases since both lipolytic and esterase activities have been described for strains of this species. No fundamental biochemical difference exists among esterases and lipases since both share a common catalytic mechanism. L. plantarum WCFS1 possesses a protein, Lp_3561, which is 44% identical to a previously described lipase, Lp_3562. In contrast to Lp_3562, Lp_3561 was unable to degrade esters possessing a chain length higher than C4 and the triglyceride tributyrin. As in other L. plantarum esterases, the electrostatic potential surface around the active site in Lp_3561 is predicted to be basic, whereas it is essentially neutral in the Lp_3562 lipase. The fact that the genes encoding both proteins were located contiguously in the L. plantarum WCFS1 genome, suggests that they originated by tandem duplication, and therefore are paralogs as new functions have arisen during evolution. The presence of the contiguous lp_3561 and lp_3562 genes was studied among L. plantarum strains. They are located in a 8,903 bp DNA fragment that encodes proteins involved in the catabolism of sialic acid and are predicted to increase bacterial adaptability under certain growth conditions

    Catalytically Active Imine-based Covalent Organic Frameworks for Detoxification of Nerve Agent Simulants in Aqueous Media

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    A series of imine-based covalent organic frameworks decorated in their cavities with di erent alkynyl, pyrrolidine, and N-methylpyrrolidine functional groups have been synthetized. These materials exhibit catalytic activity in aqueous media for the hydrolytic detoxification of nerve agents, as exemplified with nerve gas simulant diisopropylfluorophosphate (DIFP). These preliminary results suggest imine-based covalent organic frameworks (COFs) as promising materials for detoxification of highly toxic molecules.MINECO (MAT2016-77608-C3-1-P and 2-P, CTQ2017-84692-R) and EU FEDER fundin

    Uracil grafted imine-based covalent organic framework for nucleobase recognition

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    An imine-based covalent organic framework (COF) decorated in its cavities with uracil groups has shown selective recognition towards adenine in water. These results show how the confinement of the base-pair inside the COF's pores allows a remarkable selective recognition in aqueous mediaThis work was financially supported by MINECO (MAT2016-77608-C3-1-P and 2-P, SAF2017-87305-R). IMDEA Nanociencia acknowledges support from the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (MINECO, Grant SEV-2016-0686). Funding from the European Research Council (ERC-StG 279548) and MINECO (CTQ2014-27729-P and CTQ2017-84727-P) is gratefully acknowledged (DGR

    The crystal structure of galactitol-1-phosphate 5-dehydrogenase from Escherichia coli K12 provides insights into its anomalous behavior on IMAC processes

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    AbstractEndogenous galactitol-1-phosphate 5-dehydrogenase (GPDH) (EC 1.1.1.251) from Escherichia coli spontaneously interacts with Ni2+-NTA matrices becoming a potential contaminant for recombinant, target His-tagged proteins. Purified recombinant, untagged GPDH (rGPDH) converted galactitol into tagatose, and d-tagatose-6-phosphate into galactitol-1-phosphate, in a Zn2+- and NAD(H)-dependent manner and readily crystallized what has permitted to solve its crystal structure. In contrast, N-terminally His-tagged GPDH was marginally stable and readily aggregated. The structure of rGPDH revealed metal-binding sites characteristic from the medium-chain dehydrogenase/reductase protein superfamily which may explain its ability to interact with immobilized metals. The structure also provides clues on the harmful effects of the N-terminal His-tag.Structured summary of protein interactionsGPDH and GPDH bind by molecular sieving (View interaction)GPDH and GPDH bind by x-ray crystallography(View interaction)GPDH and GPDH bind by cosedimentation in solution (View interaction

    Oxaliplatin in combination with liver-specific expression of interleukin 12 reduces the immunosuppressive microenvironment of tumours and eradicates metastatic colorectal cancer in mice

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    BACKGROUND AND AIMS: New options are needed for the management and prevention of colorectal cancer liver metastases. Interleukin 12 (IL-12) is an immunostimulatory cytokine with proven antitumour effect in animal models. Despite evidence indicating its biological effect in humans, neither the recombinant protein nor gene therapy vectors expressing IL-12 have shown a relevant benefit in patients with cancer. OBJECTIVE: To develop a new approach to overcome the difficulties in obtaining a suitable expression pattern and the immunosuppressive milieu in the tumours which contribute to this poor performance. METHODS: A high-capacity ('gutless') adenoviral vector carrying a liver-specific, mifepristone (Mif)-inducible system for the expression of IL-12 (HC-Ad/RUmIL-12) was used in combination with chemotherapy. Tumours were established in the liver of C57BL/6 mice by inoculation of MC38 colon cancer cells. RESULTS: Intrahepatic injection of HC-Ad/RUmIL-12 and tailored induction regimens allowed the maintenance of safe and efficient levels of IL-12 in vivo. An individualised, stepwise increase in the dose of Mif (125-4000 μg/kg) was needed to compensate for the progressive but transient downregulation of the inducible system. Repeated cycles of Mif induction (every 24 h for 10 days) were needed for optimal tumour eradication. However, complete protection against tumour rechallenge was seen in < 25% of the animals. The administration of oxaliplatin (5 mg/kg intraperitoneally) 3 days before starting the induction regimen achieved efficient elimination of liver metastases with a single cycle of IL-12 induction, and improved protection against tumour rechallenge. This was associated with a shift in the tumour microenvironment towards a more pro-immunogenic phenotype, with an increase in the CD8+/T regulatory cell ratio and a reduction in myeloid-derived suppressor cells. These effects were not seen with 5-fluorouracil, irinotecan or gemcitabine

    Molecular aggregation of naphthalimide organic semiconductors assisted by amphiphilic and lipophilic interactions: a joint theoretical and experimental study

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    Amphiphilic and lipophilic donor–acceptor naphthalimide–oligothiophene assemblies exhibiting almost identical intramolecular properties, but differing in their intermolecular interactions, have been synthesized. Here we analyze the effect of replacing the normally used lipophilic alkyl chains with hydrophilic ones in directing molecular aggregation from an antiparallel to a parallel stacking. This different molecular packing of the amphiphilic, NIP-3TAmphi, and lipophilic, NIP-3TLipo, systems is assessed by electronic spectroscopies, scanning electronic microscopy and DFT quantum-chemical calculations. Theoretical calculations indicate that the presence of amphiphilic interactions promotes a face-to-face parallel arrangement of neighbor molecules, which induces improved electronic coupling and therefore enhances the charge transport ability and photoconducting properties of this type of materials. Time of flight and photoconducting measurements are used to determine the impact of the amphiphilic and lipophilic interactions on their possible performance in optoelectronic devices.We thank the MINECO of Spain (MAT2014-52305-P and MAT2016-77608-C3-2-P) and the UCM-BSCH joint project (GR3/14-910759), for financial support at Complutense University of Madrid. Research at University of Malaga was supported by MINECO (CTQ2015-66897-P) and Junta de Andalucia (P09-4708). R. P. O. and I. A.-M. thank the MINECO of Spain for a “Ramón y Cajal” research contract and for a predoctoral fellowship, respectively. The work performed at the University of Alicante was funded by MINECO through grant no. MAT-2011-28167-C02-01

    Genome-Wide Mapping of Histone H3 Lysine 4 Trimethylation (H3K4me3) and Its Involvement in Fatty Acid Biosynthesis in Sunflower Developing Seeds

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    15 Páginas.-- 5 Figuras.-- 3 TablasHistone modifications are of paramount importance during plant development. Investigating chromatin remodeling in developing oilseeds sheds light on the molecular mechanisms controlling fatty acid metabolism and facilitates the identification of new functional regions in oil crop genomes. The present study characterizes the epigenetic modifications H3K4me3 in relationship with the expression of fatty acid-related genes and transcription factors in developing sunflower seeds. Two master transcriptional regulators identified in this analysis, VIV1 (homologous to Arabidopsis ABI3) and FUS3, cooperate in the regulation of WRINKLED 1, a transcriptional factor regulating glycolysis, and fatty acid synthesis in developing oilseeds.This research was funded by the Spanish AEI/FEDER (UE), Project AGL2017-83449-R.Peer reviewe

    Glicosil hidrolasas de Lactiplantibacillus plantarum WCFS1

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    Resumen del trabajo presentado a la 15ª Reunión de la Red Española de Bacterias Lácticas: Bacterias Lácticas en Alimentación y Salud. Valencia, 26 y 27 de mayo de 2022.AGL2017-84614-C2-1-R y AGL2017-84614-C2-2-RPeer reviewe

    Assessment of a New ROS1 Immunohistochemistry Clone (SP384) for the Identification of ROS1 Rearrangements in Patients with Non–Small Cell Lung Carcinoma: the ROSING Study

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    Introduction: The ROS1 gene rearrangement has become an important biomarker in NSCLC. The College of American Pathologists/International Association for the Study of Lung Cancer/Association for Molecular Pathology testing guidelines support the use of ROS1 immunohistochemistry (IHC) as a screening test, followed by confirmation with fluorescence in situ hybridization (FISH) or a molecular test in all positive results. We have evaluated a novel anti-ROS1 IHC antibody (SP384) in a large multicenter series to obtain real-world data. Methods: A total of 43 ROS1 FISH-positive and 193 ROS1 FISH-negative NSCLC samples were studied. All specimens were screened by using two antibodies (clone D4D6 from Cell Signaling Technology and clone SP384 from Ventana Medical Systems), and the different interpretation criteria were compared with break-apart FISH (Vysis). FISH-positive samples were also analyzed with next-generation sequencing (Oncomine Dx Target Test Panel, Thermo Fisher Scientific). Results: An H-score of 150 or higher or the presence of at least 70% of tumor cells with an intensity of staining of 2+ or higher by the SP384 clone was the optimal cutoff value (both with 93% sensitivity and 100% specificity). The D4D6 clone showed similar results, with an H-score of at least 100 (91% sensitivity and 100% specificity). ROS1 expression in normal lung was more frequent with use of the SP384 clone (p < 0.0001). The ezrin gene (EZR)-ROS1 variant was associated with membranous staining and an isolated green signal FISH pattern (p = 0.001 and p = 0.017, respectively). Conclusions: The new SP384 ROS1 IHC clone showed excellent sensitivity without compromising specificity, so it is another excellent analytical option for the proposed testing algorithm
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