3,298 research outputs found
Molecular bases of protein halotolerance
No full textHalophilic proteins are stable and function at high salt concentration. Understanding how these molecules maintain their fold stable and avoid aggregation under harsh conditions is of great interest for biotechnological applications. This mini-review describes what is known about the molecular determinants of protein halotolerance. Comparisons between the sequences of halophilic/non-halophilic homologous protein pairs indicated that Asp and Glu are significantly more frequent, while Lys, Ile and Leu are less frequent in halophilic proteins. Homologous halophilic and non-halophilic proteins have similar overall structure, secondary structure content, and number of residues involved in the formation of H-bonds. On the other hand, on the halophilic protein surface, a decrease of nonpolar residues and an increase of charged residues are observed. Particularly, halophilic adaptation correlates with an increase of Asp and Glu, compensated by a decrease of basic residues, mainly Lys, on protein surface. A thermodynamic model, that provides a reliable explanation of the salt effect on the conformational stability of globular proteins, is presented
Mangrovivirga Sefrji & Michoud & Marasco & Merlino & Daffonchio 2021, GEN. NOV.
No full textDESCRIPTION OF MANGROVIVIRGA GEN. NOV. Mangrovivirga (Man.gro.vi.vir′ ga. N.L. neut. n. mangrovum a mangrove; L. fem. n. virga rod; N.L. fem. n. Mangrovivirga for a mangrove rod, referring to the isolation of a rod-shaped bacterium from the mangrove environment). Cells of the species are strictly aerobic, Gram-stain-negative, long-rod-shaped, moderately halophilic, non-spore-forming, non-motile, catalase-positive and oxidase-negative. The major respiratory quinone is MK7 and the major polar lipids are phosphatidylethanolamine, two unknown phospholipids and two unknown lipids. The major cellular fatty acids (>5%) are iso-C 15:0, C 16:1 ω 5 c, iso-C 17:0 and iso-C 17:0 3-OH. The G+C content of the genomic DNA is 63.1mol%. The type species is Mangrovivirga cuniculi.Published as part of Sefrji, Fatmah O., Michoud, Grégoire, Marasco, Ramona, Merlino, Giuseppe & Daffonchio, Daniele, 2021, MaNgROVIVIRga CUNICULI gen. nov., sp. nov., a moderately halophilic bacterium isolated from bioturbated Red Sea mangrove sediment, and proposal of the novel family MaNgROVIVIRgaCeae fam. nov., pp. 1-11 in International Journal of Systematic and Evolutionary Microbiology (004866) (004866) 71 (7) on page 8, DOI: 10.1099/ijsem.0.004866, http://zenodo.org/record/622410
Mangrovivirga cuniculi Sefrji & Michoud & Marasco & Merlino & Daffonchio 2021, SP. NOV.
No full textDESCRIPTION OF MANGROVIVIRGA CUNICULI SP. NOV. Mangrovivirga cuniculi (cu.ni.cu′ li. L. gen. n. cuniculi of a burrow, named because the type species was isolated from a crab burrow). The cell morphology and chemotaxonomic characteristics are given in the genus description. Cells are 0.3–0.5 µm wide and 1–1.2µm long. Its colonies are circular with a diameter of 1–2mm and feature regular edges, a smooth and shiny surface, and an orange colour caused by the production of orange carotenoids. The permissive conditions for growth are a temperature of 20–40 °C (optimum, 37°C), pH 6–10 (optimum, pH 8) and 3%–11% NaCl for salinity (optimum, 7%–9% NaCl). The carbon sources used for growth are pectin, 2-deoxy-D-ribose,Dribose, 5-keto-D-gluconic acid,L-ornithine, dihydroxyacetone, thymidine, uridine and adenosine. The genome harbours genes responsible for protection against oxidative, osmotic and salinity stresses, and includes genes encoding proteins that produce osmoprotectants and carotenoids. The cells are negative for amylase, protease, lipase, cellulase, indole, siderophore production and phosphate solubilization, and are positive for auxin (IAA) and ammonia production. The strain is unable to reduce nitrate to nitrite. The type strain, R1DC9 T (=KCTC 72349 T =JCM 33609 T =NCCB 100698 T), was isolated from bioturbated mangrove sediment at the Ibn Sina Field Research Station and Nature Conservation Area in KAUST, Saudi Arabia. The genomic DNA G+C content and genome size of the type strain are 63.1 mol% and 4661901 bp, respectively.Published as part of Sefrji, Fatmah O., Michoud, Grégoire, Marasco, Ramona, Merlino, Giuseppe & Daffonchio, Daniele, 2021, MaNgROVIVIRga CUNICULI gen. nov., sp. nov., a moderately halophilic bacterium isolated from bioturbated Red Sea mangrove sediment, and proposal of the novel family MaNgROVIVIRgaCeae fam. nov., pp. 1-11 in International Journal of Systematic and Evolutionary Microbiology (004866) (004866) 71 (7) on page 9, DOI: 10.1099/ijsem.0.004866, http://zenodo.org/record/622410
MaNgROVIVIRga CUNICULI gen. nov., sp. nov., a moderately halophilic bacterium isolated from bioturbated Red Sea mangrove sediment, and proposal of the novel family MaNgROVIVIRgaCeae fam. nov.
No full textSefrji, Fatmah O., Michoud, Grégoire, Marasco, Ramona, Merlino, Giuseppe, Daffonchio, Daniele (2021): MaNgROVIVIRga CUNICULI gen. nov., sp. nov., a moderately halophilic bacterium isolated from bioturbated Red Sea mangrove sediment, and proposal of the novel family MaNgROVIVIRgaCeae fam. nov. International Journal of Systematic and Evolutionary Microbiology (004866) 71 (7): 1-11, DOI: 10.1099/ijsem.0.004866, URL: http://dx.doi.org/10.1099/ijsem.0.00486
Characterization of MEN1309/OBT076, a new antibody conjugated to the DM4 maytansinoide toxin
No full textCD205 is a type I transmembrane glycoprotein, member of C-type lectin receptor family. Analysis by mass spectrometry revealed that CD205 antigen was robustly expressed and highly prevalent in a variety of solid malignancies of different histotypes. Immunohistochemistry (IHC) confirmed the increased expression of CD205 antigen in pancreatic, bladder and triple negative breast cancer (TNBC) malignancies compared to corresponding normal tissues. Using immunofluorescence microscopy, rapid internalization of the CD205 antigen was observed. These results supported the development of MEN1309/OBT076, a fully human CD205-targeting monoclonal antibody conjugated to DM4, a potent maytansinoid derivate, via a cleavable N-succinimidyl-4-(2-pyridyldithio) butanoate linker. MEN1309/OBT076 was characterized in vitro for target binding affinity, mechanism of action (MoA) and cytotoxic activity against a panel of cancer cell lines demonstrating selective and potent cytotoxic effects against tumor cells with strong and low to moderate CD205 antigen expression. In addition, MEN1309/OBT076 showed potent antitumor activity resulting in durable responses and complete tumor regressions in many xenografts of TNBC, pancreatic, bladder cancer cell-lines as well as in patient-derived xenograft (PDX) models. Finally, the pharmacokinetics (PK) and pharmacodynamics (PD) profile of MEN1309/OBT076 was characterized in a mouse model harboring a pancreatic tumor. Overall, these data demonstrate that MEN1309/OBT076 is a novel and selective antibody-drug conjugate (ADC) with potent activity against CD205 antigen positive tumors. These data supported the clinical development of MEN1309/OBT076 in the phase I of “SHUTTLE” clinical trial, currently ongoing
A driving force for polypeptide and protein collapse
No full textExperimental measurements and computational results have shown that polypeptide chains, made up of 15-25 glycine residues, collapse to compact structures in water at room temperature. This contrasts with the classic idea that the burial of nonpolar side chains, i.e., the hydrophobic effect, is the driving force of collapse and folding of polypeptides and proteins. It is thus necessary to find a different driving force for polyglycine collapse. The present study aims at showing that the hydrophobic effect has to be re-defined in terms of decrease in solvent-excluded volume associated with chain collapse so that it is characterized by a gain in translational entropy of water molecules. This indicates that the presence of nonpolar side chains is not so important for polypeptide and protein collapse, even though it may be fundamental for the attainment of a unique folded structure
Neural-Network Based Approach for Real-Time Control of BMEP and MFB50 in a Euro 6 Diesel Engine
No full textA real-time approach has been developed and assessed to control BMEP (brake mean effective pressure) and MFB50 (crank angle at which 50% of fuel mass has burnt) in a Euro 6 1.6L GM diesel engine. The approach is based on the use of feed-forward ANNs (artificial neural networks), which have been trained using virtual tests simulated by a previously developed low-throughput physical engine model. The latter is capable of predicting the heat release and the in-cylinder pressure, as well as the related metrics (MFB50, IMEP - indicated mean effective pressure) on the basis of an improved version of the accumulated fuel mass approach. BMEP is obtained from IMEP taking into account friction losses. The low-throughput physical model does not require high calibration effort and is also suitable for control-oriented applications. However, control tasks characterized by stricter demands in terms of computational time may require a modeling approach characterized by a further lower throughput. To this aim, feed-forward NNs have been trained to predict MFB50 and BMEP using a large dataset of virtual tests generated by the well-calibrated low-throughput physical engine model. The real-time approach has also been applied to derive the start of injection of the main pulse and the injected fuel quantity to achieve specific targets of MFB50 and BMEP. The accuracy of the real-time approach has been assessed based on experimental data taken at GM-GPS (General Motors - Global Propulsion Systems) facilities and its computational time has been compared to that of the low-throughput physical engine model, at steady-state and transient conditions over the WLTP cycle. Copyright © 2017 SAE International
Stabilization and Binding of [V4O12]4- and Unprecedented [V20O54(NO3)]n- to Lysozyme upon Loss of Ligands and Oxidation of the Potential Drug VIVO(acetylacetonato)2
No full textHigh-resolution crystal structures of lysozyme in the presence of the potential drug VIVO(acetylacetonato)2 under two different experimental conditions have been solved. The crystallographic study reveals the loss of the ligands, the oxidation of VIV to VV and the subsequent formation of adducts of the protein with two different polyoxidovanadates: [V4O12]4-, which interacts with lysozyme non-covalently, and the unprecedented [V20O54(NO3)]n-, which is covalenty bound to the side chain of an aspartate residue of symmetry related molecules
Stabilization and Binding of [V4O12]4− and Unprecedented [V20O54(NO3)]n− to Lysozyme upon Loss of Ligands and Oxidation of the Potential Drug VIVO(acetylacetonato)2
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