Ferreira, P, Cerqueira NMFSA, Coelho C, Fernandes PA, Romão MJ, Ramos MJ.
2019.
New insights about the monomer and homodimer structures of the human AOX1, 2019. Physical Chemistry Chemical Physics. 21(25):13545-13554.: The Royal Society of Chemistry
AbstractHuman aldehyde oxidase (hAOX1) is a molybdenum dependent enzyme that plays an important role in the metabolism of various compounds either endogenous or xenobiotics. Due to its promiscuity, hAOX1 plays a major role in the pharmacokinetics of many drugs and therefore has gathered a lot of attention from the scientific community and, particularly, from the pharmaceutical industry. In this work, homology modelling, molecular docking and molecular dynamics simulations were used to study the structure of the monomer and dimer of human AOX. The results with the monomer of hAOX1 allowed to shed some light on the role played by thioridazine and two malonate ions that are co-crystalized in the recent X-ray structure of hAOX1. The results show that these molecules endorse several conformational rearrangements in the binding pocket of the enzyme and these changes have an impact in the active site topology as well as in the stability of the substrate (phthalazine). The results show that the presence of both molecules open two gates located at the entrance of the binding pocket, from which results the flooding of the active site. They also endorse several modifications in the shape of the binding pocket (namely the position of Lys893) that, together with the presence of the solvent molecules, favour the release of the substrate to the solvent. Further insights were also obtained with the assembled homodimer of hAOX1. The allosteric inhibitor (THI) binds closely to the region where the dimerization of both monomers occur. These findings suggest that THI can interfere with protein dimerization.
Kourmentza, C, Araujo D, Sevrin C, Roma-Rodriques C, Lia Ferreira J, Freitas F, Dionisio M, Baptista PV, Fernandes AR, Grandfils C, Reis MAM.
2019.
Occurrence of non-toxic bioemulsifiers during polyhydroxyalkanoate production by Pseudomonas strains valorizing crude glycerol by-product, 2019. Bioresour Technol. 281:31-40.
AbstractWhile screening for polyhydroxyalkanoate (PHA) producing strains, using glycerol rich by-product as carbon source, it was observed that extracellular polymers were also secreted into the culture broth. The scope of this study was to characterize both intracellular and extracellular polymers, produced by Pseudomonas putida NRRL B-14875 and Pseudomonas chlororaphis DSM 50083, mostly focusing on those novel extracellular polymers. It was found that they fall into the class of bioemulsifiers (BE), as they showed excellent emulsion stability against different hydrocarbons/oils at various pH conditions, temperature and salinity concentrations. Cytotoxicity tests revealed that BE produced by P. chlororaphis inhibited the growth of highly pigmented human melanoma cells (MNT-1) by 50% at concentrations between 150 and 200mug/mL, while no effect was observed on normal skin primary keratinocytes and melanocytes. This is the first study reporting mcl-PHA production by P. putida NRRL B-14785 and bioemulsifier production from both P. putida and P. chlororaphis strains.
Choroba, K, Machura B, Raposo LR, Malecki JG, Kula S, Pajak M, Erfurt K, Maron AM, Fernandes AR.
2019.
Platinum(ii) complexes showing high cytotoxicity toward A2780 ovarian carcinoma cells, 2019. Dalton Trans. 48(34):13081-13093.
Abstract2,6-Bis(thiazol-2-yl)pyridines functionalized with 9-anthryl (L(1)), 9-phenanthryl (L(2)), and 1-pyrenyl (L(3)) groups were used for the preparation of [Pt(L(n))Cl]CF3SO3 (1-3). The constitution of the Pt(ii) complexes was determined by (1)H and (13)C NMR spectroscopy, HR-MS spectrometry, elemental analysis and X-ray analysis (for (1)). The electrochemical and photophysical properties of [Pt(L(n))Cl]CF3SO3 were compared with the behaviour of the Pt(ii) complexes with aryl-substituted 2,2':6',2''-terpyridine ligands. What is noteworthy is that the coordination ability of dtpy toward the Pt(ii) centre was investigated for the first time. All complexes were tested in vitro by MTS assay on four tumor cell lines, A2780 (ovarian carcinoma), HTC116 (colon rectal carcinoma), MCF7 (breast adenocarcinoma), and PC3 (prostate carcinoma) and on normal primary fibroblasts. Compounds (1-3) showed a dose dependent antiproliferative effect in the A2780 cell line with (3) > (2) > (1) and this loss of A2780 cell viability was due to a combination of an apoptotic cell death mechanism via mitochondria and autophagic cell death. Exposure to IC50 concentration of (2) induced an increase in the number of apoptotic nuclei and a depolarization of the mitochondrial membrane which is consistent with the induction of apoptosis while exposure to IC50 concentration of (3) showed an increase in the apoptotic nuclei with a slight hyperpolarization of the mitochondrial membrane that might indicate an initial step of apoptosis induction. The complexes (2) and (3) induce an increase in the production of intracellular ROS which is associated with the trigger of the apoptotic pathways. The ROS production was augmented by the presence of oxidants and correlated with an increase of oxygen radicals. The IC50 of (2) and (3) (4.4 muM and 2.9 muM, respectively) was similar to the IC50 of cisplatin (3.4 muM) in the A2780 cell line, which together with their low cytotoxicity in normal fibroblasts, demonstrates their potential for further studies.
Almeida, APC, Querciagrossa L, Silva PES, Gonçalves F, Canejo JP, Almeida PL, Godinho MH, Zannoni C.
2019.
Reversible water driven chirality inversion in cellulose-based helices isolated from Erodium awns, 2019. Soft Matter. 15(13):2838-2847.: The Royal Society of Chemistry
AbstractAmong the movements observed in some cellulosic structures produced by plants are those that involve the dispersion and burial of seeds, as for example in Erodium from the Geraniaceae plant family. Here we report on a simple and efficient strategy to isolate and tune cellulose-based hygroscopic responsive materials from Erodium awns’ dead tissues. The stimuli-responsive material isolated forms left-handed (L) or right-handed (R) helical birefringent transparent ribbons in the wet state that reversibly change to R helices when the material dries. The humidity-driven motion of dead tissues is most likely due to a composite material made of cellulose networks of fibrils imprinted by the plant at the nanoscale, which reinforces a soft wall polysaccharide matrix. The inversion of the handedness is explained using computational simulations considering filaments that contract and expand asymmetrically. The awns of Erodium are known to present hygroscopic movements, forming R helices in the dry state, but the possibility of actuating chirality via humidity suggests that these cellulose-based skeletons, which do not require complicated lithography and intricate deposition techniques, provide a diverse range of applications from intelligent textiles to micro-machines.
Alves-Barroco, C, Roma-Rodrigues C, Raposo LR, Bras C, Diniz M, Caco J, Costa PM, Santos-Sanches I, Fernandes AR.
2019.
Streptococcus dysgalactiae subsp. dysgalactiae isolated from milk of the bovine udder as emerging pathogens: In vitro and in vivo infection of human cells and zebrafish as biological models, 2019. Microbiologyopen. 8(1):e00623.
AbstractStreptococcus dysgalactiae subsp. dysgalactiae (SDSD) is a major cause of bovine mastitis and has been regarded as an animal-restricted pathogen, although rare infections have been described in humans. Previous studies revealed the presence of virulence genes encoded by phages of the human pathogen Group A Streptococcus pyogenes (GAS) in SDSD isolated from the milk of bovine udder with mastitis. The isolates SDSD VSD5 and VSD13 could adhere and internalize human primary keratinocyte cells, suggesting a possible human infection potential of bovine isolates. In this work, the in vitro and in vivo potential of SDSD to internalize/adhere human cells of the respiratory track and zebrafish as biological models was evaluated. Our results showed that, in vitro, bovine SDSD strains could interact and internalize human respiratory cell lines and that this internalization was dependent on an active transport mechanism and that, in vivo, SDSD are able to cause invasive infections producing zebrafish morbidity and mortality. The infectious potential of these isolates showed to be isolate-specific and appeared to be independent of the presence or absence of GAS phage-encoded virulence genes. Although the infection ability of the bovine SDSD strains was not as strong as the human pathogenic S. pyogenes in the zebrafish model, results suggested that these SDSD isolates are able to interact with human cells and infect zebrafish, a vertebrate infectious model, emerging as pathogens with zoonotic capability.
Almeida, J, Roma-Rodrigues C, Mahmoud AG, Guedes da Silva MFC, Pombeiro AJL, Martins LMDRS, Baptista PV, Fernandes AR.
2019.
Structural characterization and biological properties of silver(I) tris(pyrazolyl)methane sulfonate, 2019. J Inorg Biochem. 199:110789.
AbstractThe water-soluble 1D helical coordination polymer [Ag(Tpms)]n (1) [Tpms=tris(pyrazolyl)methane sulfonate, (-)O3SC(pz)3; pz=pyrazolyl] was synthesized and fully characterized, its single-crystal X-ray diffraction analysis revealing the ligand acting as a bridging chelate N3-donor ligand. The antiproliferative potential of 1 was performed on two human tumour cell lines, A2780 and HCT116, and in normal fibroblasts, with a much higher effect in the former cell line (IC50 of 0.04muM) as compared to the latter cell line and to normal fibroblasts. Compound 1 does not alter cell cycle progression but interferes with the adherence of A2780 cells triggering cell apoptosis. Apoptosis appears to occur via the extrinsic pathway (no changes in mitochondria membrane potential, reactive oxygen species (ROS) and pro-apoptotic (B-cell lymphoma 2 (BCL-2) associated protein (BAX))/anti-apoptotic (BCL-2) ratio) being this hypothesis also supported by the presence of silver mainly in the supernatants of A2780 cells. Results also indicated that cell death via autophagy was triggered. Proteomic analysis allowed us to confirm that compound 1 is able to induce a stress response in A2780 cells that is related with its antiproliferative activity and the trigger of apoptosis.
Marques, AC, Miglietta D, Gaspar G, Baptista AC, Gaspar A, Perdigão A, Soares I, Bianchi C, Sousa D, Morais Faustino BM, Amaral VS, Santos T, Gonçalves AP, da Silva RC, Giorgis F, Ferreira I.
2019.
Synthesis of thermoelectric magnesium-silicide pastes for 3D printing, electrospinning and low-pressure spray. Materials for Renewable and Sustainable Energy. :8-21.
Fernandes, C, Pina AS, Barbosa AJM, Padrão I, Duarte F, Andreia C, Teixeira S, Alves V, Gomes P, Fernandes TG, Dias AMGC, Roque ACA.
2019.
Affinity‐triggered assemblies based on a designed peptide‐peptide affinity pair. Biotechnology Journal. -(-):-.
AbstractAffinity‐triggered assemblies rely on affinity interactions as the driving force to assemble physically‐crosslinked networks. WW domains are small hydrophobic proteins binding to proline‐rich peptides that are typically produced in the insoluble form. Previous works attempted the biological production of the full WW domain in tandem to generate multivalent components for affinity‐triggered hydrogels. In this work, an alternative approach was followed by engineering a 13‐mer minimal version of the WW domain that retains the ability to bind to target proline‐rich peptides. Both ligand and target peptides were produced chemically and conjugated to multivalent polyethylene glycol, yielding two components. Upon mixing, they together form soft biocompatible affinity‐triggered assemblies, stable in stem cell culture media, and displaying mechanical properties in the same order of magnitude as for those hydrogels formed with the full WW protein in tandem.
Santos, Â, Otero V, Vilarigues M.
2019.
Characterisation of glass and painting materials from 18th century hand-painted glass slides used for projection with Magic Lanterns. Interim Meeting of the ICOM-CC Glass and Ceramics Working Group − "Recent Advances in Glass and Ceramics Conservation 2019". :219-224., London, England, 5-7 September 2019
AbstractWith the invention of the Magic Lantern during the 17th century, new perspectives for the pre-cinema universe started to emerge. During the following two centuries, this instrument achieved extraordinary success on all social media.
One of the first stages of the production of glass slides for projection with magic lanterns was the hand-painting technique that nowadays represents a significant challenge for conservation professionals due to the diversity of painting materials used and their exposure to aggressive conditions during the projections.
A set of Italian 18th-century hand-painted glass slides from the Cinemateca Portuguesa – Museu do Cinema's collection are currently being studied. The glass was characterised using Energy Dispersive X-Ray Fluorescence Spectrometry (µ-EDXRF) and the identification of the painting materials was performed by Fourier Transform Infrared Spectroscopy (µ-FTIR) and Raman Spectroscopy (µ-Raman). Further investigation will be conducted with Optical Microscopy (OM), UV-Vis Fibre-Optic Reflectance Spectroscopy (FORS), and Microspectrofluorimetry.
The combination of different analytical techniques on glass slides examples allowed us to identify the composition of the glass and paintings materials, as well as to determine their current state of preservation.
Machado, MA, Antin K-N, Rosado LS, Vilaça P, Santos TG.
2019.
Contactless high-speed eddy current inspection of unidirectional carbon fiber reinforced polymer. Composites Part B: Engineering. 168:226-235.
AbstractThis paper presents the development and the results of a customized eddy current (EC) non-destructive testing (NDT) system for highly demanding online inspection conditions. Several planar eddy current array probes were designed, numerically simulated and experimentally compared for the inspection of low conductivity unidirectional carbon fibre reinforced polymer (CFRP) ropes. The inspections were performed using a dedicated scanner device at 4 m/s with 3 mm probe lift-off where defects under 1 mm were detected with an excellent SNR. Different defect morphologies and sizes, such as broken fibres and lateral cuts, were successful detected and compared to conventional probes.