| 1. |
- Kuktaite, Ramune, et al.
(författare)
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Structure and Morphology of Wheat Gluten Films : From Polymeric Protein Aggregates toward Superstructure Arrangements
- 2011
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 12:5, s. 1438-1448
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Tidskriftsartikel (refereegranskat)abstract
- Evaluation of structure and morphology of extruded wheat gluten (WG) films showed WG protein assemblies elucidated on a range of length scales from nano (4.4 angstrom and 9 to 10 angstrom, up to 70 angstrom) to micro (10 mu m). The presence of NaOH in WG films induced a tetragonal structure with unit cell parameters, a = 51.85 angstrom and c = 40.65 angstrom, whereas NH4OH resulted in a bidimensional hexagonal close-packed (HCP) structure with a lattice parameter of 70 angstrom. In the WG films with NH4OH, a highly polymerized protein pattern with intimately mixed glutenins and gliadins bounded through SH/SS interchange reactions was found. A large content of beta-sheet structures was also found in these films, and the film structure was oriented in the extrusion direction. In conclusion, this study highlights complexities of the supramolecular structures and conformations of wheat gluten polymeric proteins in biofilms not previously reported for biobased materials.
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| 2. |
- Schulze, Yves, et al.
(författare)
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Chemical-genomic profiling identifies genes that protect yeast from aluminium, gallium, and indium toxicity
- 2023
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Ingår i: Metallomics. - : Oxford University Press. - 1756-5901 .- 1756-591X. ; 15:6
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Tidskriftsartikel (refereegranskat)abstract
- Aluminium, gallium, and indium are group 13 metals with similar chemical and physical properties. While aluminium is one of the most abundant elements in the Earth's crust, gallium and indium are present only in trace amounts. However, the increased use of the latter metals in novel technologies may result in increased human and environmental exposure. There is mounting evidence that these metals are toxic, but the underlying mechanisms remain poorly understood. Likewise, little is known about how cells protect themselves from these metals. Aluminium, gallium, and indium are relatively insoluble at neutral pH, and here we show that they precipitate in yeast culture medium at acidic pH as metal-phosphate species. Despite this, the dissolved metal concentrations are sufficient to induce toxicity in the yeast Saccharomyces cerevisiae. By chemical-genomic profiling of the S. cerevisiae gene deletion collection, we identified genes that maintain growth in the presence of the three metals. We found both shared and metal-specific genes that confer resistance. The shared gene products included functions related to calcium metabolism and Ire1/Hac1-mediated protection. Metal-specific gene products included functions in vesicle-mediated transport and autophagy for aluminium, protein folding and phospholipid metabolism for gallium, and chorismate metabolic processes for indium. Many of the identified yeast genes have human orthologues involved in disease processes. Thus, similar protective mechanisms may act in yeast and humans. The protective functions identified in this study provide a basis for further investigations into toxicity and resistance mechanisms in yeast, plants, and humans. © 2023 The Author(s).
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| 3. |
- Zhang, Heyang, et al.
(författare)
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Together is Better : mRNA Co-Encapsulation in Lipoplexes is Required to Obtain Ratiometric Co-Delivery and Protein Expression on the Single Cell Level
- 2022
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Ingår i: Advanced Science. - : John Wiley and Sons Inc. - 2198-3844. ; 9:4
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Tidskriftsartikel (refereegranskat)abstract
- Liposomes can efficiently deliver messenger RNA (mRNA) into cells. When mRNA cocktails encoding different proteins are needed, a considerable challenge is to efficiently deliver all mRNAs into the cytosol of each individual cell. In this work, two methods are explored to co-deliver varying ratiometric doses of mRNA encoding red (R) or green (G) fluorescent proteins and it is found that packaging mRNAs into the same lipoplexes (mingle-lipoplexes) is crucial to efficiently deliver multiple mRNA types into the cytosol of individual cells according to the pre-defined ratio. A mixture of lipoplexes containing only one mRNA type (single-lipoplexes), however, seem to follow the “first come – first serve” principle, resulting in a large variation of R/G uptake and expression levels for individual cells leading to ratiometric dosing only on the population level, but rarely on the single-cell level. These experimental observations are quantitatively explained by a theoretical framework based on the stochasticity of mRNA uptake in cells and endosomal escape of mingle- and single-lipoplexes, respectively. Furthermore, the findings are confirmed in 3D retinal organoids and zebrafish embryos, where mingle-lipoplexes outperformed single-lipoplexes to reliably bring both mRNA types into single cells. This benefits applications that require a strict control of protein expression in individual cells. © 2021 The Authors.
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| 4. |
- Sepehri, Sobhan, 1986, et al.
(författare)
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Characterization of Binding of Magnetic Nanoparticles to Rolling Circle Amplification Products by Turn-On Magnetic Assay
- 2019
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Ingår i: Biosensors-Basel. - : MDPI AG. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- The specific binding of oligonucleotide-tagged 100 nm magnetic nanoparticles (MNPs) to rolling circle products (RCPs) is investigated using our newly developed differential homogenous magnetic assay (DHMA). The DHMA measures ac magnetic susceptibility from a test and a control samples simultaneously and eliminates magnetic background signal. Therefore, the DHMA can reveal details of binding kinetics of magnetic nanoparticles at very low concentrations of RCPs. From the analysis of the imaginary part of the DHMA signal, we find that smaller MNPs in the particle ensemble bind first to the RCPs. When the RCP concentration increases, we observe the formation of agglomerates, which leads to lower number of MNPs per RCP at higher concentrations of RCPs. The results thus indicate that a full frequency range of ac susceptibility observation is necessary to detect low concentrations of target RCPs and a long amplification time is not required as it does not significantly increase the number of MNPs per RCP. The findings are critical for understanding the underlying microscopic binding process for improving the assay performance. They furthermore suggest DHMA is a powerful technique for dynamically characterizing the binding interactions between MNPs and biomolecules in fluid volumes.
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| 5. |
- Carlred, Louise M, 1985, et al.
(författare)
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Probing Amyloid-β Pathology in transgenic Alzheimer's disease (tgArcSwe) mice using MALDI Imaging Mass Spectrometry
- 2016
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Ingår i: Journal of neurochemistry. - : Wiley. - 1471-4159 .- 0022-3042. ; 138:3, s. 469-478
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Tidskriftsartikel (refereegranskat)abstract
- The pathological mechanisms underlying Alzheimer's disease (AD) are still not understood. The disease pathology is characterized by accumulation and aggregation of amyloid-β (Aβ) peptides into extracellular plaques, however the factors that promote neurotoxic Aβ aggregation remain elusive. Imaging mass spectrometry (IMS) is a powerful technique to comprehensively elucidate the spatial distribution patterns of lipids, peptides and proteins in biological tissues. In the present study, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) based imaging was used to study Aβ deposition in transgenic mouse brain tissue and to elucidate the plaque associated chemical microenvironment. The imaging experiments were performed in brain sections of transgenic Alzheimer's disease mice carrying the Arctic and Swedish mutation of amyloid-beta precursor protein (tgArcSwe). Multivariate image analysis was used to interrogate the IMS data for identifying pathologically relevant, anatomical features based on their chemical identity. This include cortical and hippocampal Aβ deposits, whose amyloid peptide content was further verified using immunohistochemistry and laser micro dissection followed by MALDI MS analysis. Subsequent statistical analysis on spectral data of regions of interest (ROI) revealed brain region specific differences in Aβ peptide aggregation. Moreover, other plaque associated protein species were identified including macrophage migration inhibitory factor (MIF) suggesting neuroinflammatory processes and glial cell reactivity to be involved in AD pathology. The presented data further highlight the potential of IMS as powerful approach in neuropathology.
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| 6. |
- Warwas, Niklas, et al.
(författare)
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Marine yeast (Candida sake) cultured on herring brine side streams is a promising feed ingredient and omega-3 source for rainbow trout (Oncorhynchus mykiss)
- 2023
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Ingår i: Aquaculture. - : Elsevier BV. - 0044-8486 .- 1873-5622. ; 571
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Tidskriftsartikel (refereegranskat)abstract
- A major challenge for the aquaculture industry is the supply of sustainable feeds. A promising model to achieve this is to utilize circular flows where feed ingredients, such as single cell protein, are cultivated using side streams of the food industry. The aim of this study was to evaluate the marine yeast Candida sake, produced on herring brine side streams, as a source of protein and immune stimulant in feed for salmonid fish. The dry C. sake product contained 54% protein (3.3% lysine and 0.8% methionine) and 13% lipids (1.1% eicosapentaenoic, EPA, and 1% docosahexaenoic acid, DHA). Four experimental diets were designed and tested in a 9-week feeding trial using juvenile rainbow trout (Oncorhynchus mykiss). A control diet containing both fish and plant-based ingredients constituted the base feed to which 20% (to evaluate effects on digestibility, growth and intestinal physiology), 20% heat-treated (to evaluate effects of downstream processing) and 3% (to evaluate immune stimulatory properties, replacing 3% soy protein concentrate) C. sake was added. The apparent digestibility coefficient of C. sake for protein, fat and gross energy was above 80%, and for amino acids above 90% regardless of treatment, suggesting a high bioavailability of C. sake. All three yeast containing diets performed equally to the control regarding specific growth rate, feed conversion ratio and functional intestinal health. These results suggest that C. sake is a promising alternative protein source for circular feeds in the salmonid industry. The presence of EPA and DHA represents an added value. The heat treatment increased the apparent digestibility coefficient of dry matter by 8% but decreased amino acid digestibility by on average 3%, indicating that heat treatment may not be the optimal downstream processing technique. Furthermore, the inclusion of 3% C. sake increased the intestinal lamina propria width and TGF-beta transcription, indicating an immune stimulating effect. Future research is needed to understand these immune modulatory effects of C. sake supplementation.
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| 7. |
- Hulander, Mats, et al.
(författare)
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Gradients in surface nanotopography used to study platelet adhesion and activation
- 2013
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Ingår i: Colloids and Surfaces B-Biointerfaces. - : Elsevier BV. - 0927-7765 .- 1873-4367. ; 110, s. 261-269
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Tidskriftsartikel (refereegranskat)abstract
- Gradients in surface nanotopography were prepared by adsorbing gold nanoparticles on smooth gold substrates using diffusion technique. Following a sintering procedure the particle binding chemistry was removed, and integration of the particles into the underlying gold substrate was achieved, leaving a nanostructured surface with uniform surface chemistry. After pre-adsorption of human fibrinogen, the effect of surface nanotopography on platelets was studied. The use of a gradient in nanotopography allowed for platelet adhesion and activation to be studied as a function of nanoparticle coverage on one single substrate. A peak in platelet adhesion was found at 23% nanoparticle surface coverage. The highest number of activated platelets was found on the smooth control part of the surface, and did not coincide with the number of adhered platelets. Activation correlated inversely with particle coverage, hence the lowest fraction of activated platelets was found at high particle coverage. Hydrophobization of the gradient surface lowered the total number of adhering cells, but not the ratio of activated cells. Little or no effect was seen on gradients with 36 nm particles, suggesting the existence of a lower limit for sensing of surface nano-roughness in platelets. These results demonstrate that parameters such as ratio between size and inter-particle distance can be more relevant for cell response than wettability on nanostructured surfaces. The minor effect of hydrophobicity, the generally reduced activation on nanostructured surfaces and the presence of a cut-off in activation of human platelets as a function of nanoparticle size could have implications for the design of future blood-contacting biomaterials.
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| 8. |
- Michel, M., et al.
(författare)
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Small-molecule activation of OGG1 increases oxidative DNA damage repair by gaining a new function
- 2022
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Ingår i: Science. - Stockholm : American Association for the Advancement of Science. - 0036-8075 .- 1095-9203. ; 376:6600, s. 1471-1476
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Tidskriftsartikel (refereegranskat)abstract
- Oxidative DNA damage is recognized by 8-oxoguanine (8-oxoG) DNA glycosylase 1 (OGG1), which excises 8-oxoG, leaving a substrate for apurinic endonuclease 1 (APE1) and initiating repair. Here, we describe a small molecule (TH10785) that interacts with the phenylalanine-319 and glycine-42 amino acids of OGG1, increases the enzyme activity 10-fold, and generates a previously undescribed b,d-lyase enzymatic function. TH10785 controls the catalytic activity mediated by a nitrogen base within its molecular structure. In cells, TH10785 increases OGG1 recruitment to and repair of oxidative DNA damage. This alters the repair process, which no longer requires APE1 but instead is dependent on polynucleotide kinase phosphatase (PNKP1) activity. The increased repair of oxidative DNA lesions with a small molecule may have therapeutic applications in various diseases and aging. © 2022 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works
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| 9. |
- Olsen, Elisabeth K., et al.
(författare)
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Marine AChE inhibitors isolated from Geodia barretti : Natural compounds and their synthetic analogs
- 2016
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Ingår i: Organic and biomolecular chemistry. - : Royal Society of Chemistry. - 1477-0520 .- 1477-0539. ; 14:5, s. 1629-1640
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Tidskriftsartikel (refereegranskat)abstract
- Barettin, 8,9-dihydrobarettin, bromoconicamin and a novel brominated marine indole were isolated from the boreal sponge Geodia barretti collected off the Norwegian coast. The compounds were evaluated as inhibitors of electric eel acetylcholinesterase. Barettin and 8,9-dihydrobarettin displayed significant inhibition of the enzyme, with inhibition constants (Ki) of 29 and 19 μM respectively towards acetylcholinesterase via a reversible noncompetitive mechanism. These activities are comparable to those of several other natural acetylcholinesterase inhibitors of marine origin. Bromoconicamin was less potent against acetylcholinesterase, and the novel compound was inactive. Based on the inhibitory activity, a library of 22 simplified synthetic analogs was designed and prepared to probe the role of the brominated indole, common to all the isolated compounds. From the structure-activity investigation it was shown that the brominated indole motif is not sufficient to generate a high acetylcholinesterase inhibitory activity, even when combined with natural cationic ligands for the acetylcholinesterase active site. The four natural compounds were also analysed for their butyrylcholinesterase inhibitory activity in addition and shown to display comparable activities. The study illustrates how both barettin and 8,9-dihydrobarettin display additional bioactivities which may help to explain their biological role in the producing organism. The findings also provide new insights into the structure-activity relationship of both natural and synthetic acetylcholinesterase inhibitors.
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| 10. |
- Urbancsok, János, et al.
(författare)
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Flexure wood formation via growth reprogramming in hybrid aspen involves jasmonates and polyamines and transcriptional changes resembling tension wood development
- 2023
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Ingår i: New Phytologist. - : John Wiley & Sons. - 0028-646X .- 1469-8137. ; 240:6, s. 2312-2334
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Tidskriftsartikel (refereegranskat)abstract
- Stem bending in trees induces flexure wood but its properties and development are poorly understood. Here, we investigated the effects of low-intensity multidirectional stem flexing on growth and wood properties of hybrid aspen, and on its transcriptomic and hormonal responses.Glasshouse-grown trees were either kept stationary or subjected to several daily shakes for 5 wk, after which the transcriptomes and hormones were analyzed in the cambial region and developing wood tissues, and the wood properties were analyzed by physical, chemical and microscopy techniques.Shaking increased primary and secondary growth and altered wood differentiation by stimulating gelatinous-fiber formation, reducing secondary wall thickness, changing matrix polysaccharides and increasing cellulose, G- and H-lignin contents, cell wall porosity and saccharification yields. Wood-forming tissues exhibited elevated jasmonate, polyamine, ethylene and brassinosteroids and reduced abscisic acid and gibberellin signaling. Transcriptional responses resembled those during tension wood formation but not opposite wood formation and revealed several thigmomorphogenesis-related genes as well as novel gene networks including FLA and XTH genes encoding plasma membrane-bound proteins.Low-intensity stem flexing stimulates growth and induces wood having improved biorefinery properties through molecular and hormonal pathways similar to thigmomorphogenesis in herbaceous plants and largely overlapping with the tension wood program of hardwoods.
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