19 research outputs found
Aggregation properties of a therapeutic peptide for rheumatoid arthritis: a spectroscopic and molecular dynamics study
The biological properties of therapeutic peptides, such as their pharmacokinetics and pharmacodynamics, are correlated with their structure and aggregation properties. Herein, we studied the aggregation properties of a therapeutic peptide (CIGB-814), currently in phase 2 clinical trial, for the treatment of rheumatoid arthritis over a wide range of concentrations (ÎŒMâmM). We applied spectroscopic techniques (fluorescence, circular dichro- ism, resonance, and dynamic light scattering), atomic force microscopy, and molecular dynamics simulations to determine the aggregation mechanism of CIGB-814. We found that the hierarchical aggregation of CIGB-814 at micromolar concentrations was initiated by the formation of peptide oligomers. Subsequently, the peptide oligomers trigger the nucleation and growth of peptide nanostructures (cac = 123 ÎŒM), ultimately leading to the fibrillization of CIGB-814 (cacâ = 508 ÎŒM). These results pave the way for a deeper understanding of the CIGB-814 therapeutic activity and may give important insights on its pharmacokinetics
Part 4: Pediatric basic and advanced life support 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care
Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk
BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7Ă10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4Ă10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4Ă10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat
Scaling-up fermentation of Escherichia coli for production of recombinant P64k protein from Neisseria meningitidis
Background: P64k is a Neisseria meningitidis high molecular weight protein present in meningococcal vaccine preparations. The lpdA gene, which encodes for this protein, was cloned in Escherichia coli and the P64k recombinant protein was expressed in E. coli K12 GC366 cells under the control of a tryptophan promoter. P64k was expressed as an intracellular soluble protein about 28% of the total cellular protein. Several scale-up criteria of fermentation processes were studied to obtain the recombinant P64k protein at the pilot production scale. Results: The best operational conditions at a larger scale production of P64k recombinant protein were studied and compared using the four following criteria: Constant Reynold's number (Re constant), Constant impeller tip speed (n di constant), Constant power consumption per unit liquid volume (P/V constant) and Constant volumetric oxygen transfer coefficients (KLa/k constant). The highest production of the recombinant protein was achieved based on the constant KLa/k scale-up fermentation criterion, calculating the aeration rate (Q) and the impeller agitation speed (n) by iterative process, keeping constant the KLa/k value from bench scale. The P64k protein total production at the 50 l culture scale was 546 mg l-1 in comparison with the 284 mg l-1 obtained at 1.5 l bench scale. Conclusions: The methodology described herein, for the KLa/k scale-up fermentation criterion, allowed us to obtain the P64k protein at 50 l scale. A fermentation process for the production of P64k protein from N. meningitidis was established, a protein to be used in future vaccine formulations in humans.How to cite: Espinosa R, GarcĂa J, Narciandi E, et al. Scaling-up fermentation of Escherichia coli for production of recombinant P64k protein from Neisseria meningitidis. Electron J Biotechnol 2018;33. https://doi.org/10.1016/j.ejbt.2018.03.004. Keywords: Escherichia coli, Fermentation process, Fermentation, Gram negative diplococcus, High molecular weight protein, Meningococcal vaccine, Neisseria meningitidis, Obligate human pathogen, Recombinant P64k protein, Scale-up, Tryptophan promote
Heterologous Expression, Purification and Immunoreactivity of the Antigen 5 from Polybia paulista Wasp Venom
Polybia paulista (Hymenoptera: Vespidae) is responsible for a high number of sting accidents and anaphylaxis events in Southeast Brazil, Argentina and Paraguay. The specific detection of allergy to the venom of this wasp is often hampered by the lack of recombinant allergens currently available for molecular diagnosis. Antigen 5 (~23 kDa) from P. paulista venom (Poly p 5) is a highly abundant and glycosylated allergenic protein that could be used for development of component-resolved diagnosis (CRD). Here, we describe the cloning and heterologous expression of the antigen 5 (rPoly p 5) from P. paulista venom using the eukaryotic system Pichia pastoris. The expression as a secreted protein yielded high levels of soluble rPoly p 5. The recombinant allergen was further purified to homogeneity (99%) using a two-step chromatographic procedure. Simultaneously, the native form of the allergen (nPoly p 5) was purified from the wasp venom by Ion exchange chromatography. The rPoly p 5 and nPoly p 5 were then submitted to a comparative analysis of IgE-mediated immunodetection using sera from patients previously diagnosed with sensitization to wasp venoms. Both rPoly p 5 and nPoly p 5 were recognized by specific IgE (sIgE) in the sera of the allergic individuals. The high levels of identity found between nPoly p 5 and rPoly p 5 by the alignment of its primary sequences as well as by 3-D models support the results obtained in the immunoblot. Overall, we showed that P. pastoris is a suitable system for production of soluble rPoly p 5 and that the recombinant allergen represents a potential candidate for molecular diagnosis of P.paulista venom allergy
Molecular cloning, expression and IgE-immunoreactivity of phospholipase A1, a major allergen from Polybia paulista (hymenoptera: vespidae) venom
Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES)Polybia paulista (Hymenoptera: Vespidae) is a clinically relevant social wasp that frequently causes stinging accidents in southeast Brazil. To date, diagnosis and specific immunotherapy (SIT) of allergy are based on the use of crude venom extracts. Produ1244452FAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOCAPES - COORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL DE NĂVEL SUPERIORFundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES)2006/54799-6; 2014/13936- 7; 2009/51539-101197/ 10-DF
Proteomic Study to Survey the CIGB-552 Antitumor Effect
CIGB-552 is a cell-penetrating peptide that exerts in vitro and in vivo antitumor effect on cancer cells. In the present work, the mechanism involved in such anticancer activity was studied using chemical proteomics and expression-based proteomics in culture cancer cell lines. CIGB-552 interacts with at least 55 proteins, as determined by chemical proteomics. A temporal differential proteomics based on iTRAQ quantification method was performed to identify CIGB-552 modulated proteins. The proteomic profile includes 72 differentially expressed proteins in response to CIGB-552 treatment. Proteins related to cell proliferation and apoptosis were identified by both approaches. In line with previous findings, proteomic data revealed that CIGB-552 triggers the inhibition of NF-ÎșB signaling pathway. Furthermore, proteins related to cell invasion were differentially modulated by CIGB-552 treatment suggesting new potentialities of CIGB-552 as anticancer agent. Overall, the current study contributes to a better understanding of the antitumor action mechanism of CIGB-552