25 research outputs found
Chlorinated phenols control the expression of the multidrug resistance efflux pump MexABâOprM in Pseudomonas aeruginosa by interacting with NalC
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91122/1/MMI_7544_sm_FigS1-4_TabS1-2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/91122/2/j.1365-2958.2011.07544.x.pd
Are Zinc-Finger Domains of Protein Kinase C Dynamic Structures That Unfold by Lipid or Redox Activation?
Protein kinase C (PKC) is activated by lipid second messengers or redox action, raising the question whether these activation modes involve the same or alternate mechanisms. Here we show that both lipid activators and oxidation target the zinc-finger domains of PKC, suggesting a unifying activation mechanism. We found that lipid agonist-binding or redox action leads to zinc release and disassembly of zinc fingers, thus triggering large-scale unfolding that underlies conversion to the active enzyme. These results suggest that PKC zinc fingers, originally considered purely structural devices, are in fact redox-sensitive flexible hinges, whose conformation is controlled both by redox conditions and lipid agonists. Antioxid. Redox Signal. 14, 757-766.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90473/1/ars-2E2010-2E3773.pd
Recommended reading list of early publications on atomic layer deposition-Outcome of the "Virtual Project on the History of ALD"
Atomic layer deposition (ALD), a gas-phase thin film deposition technique based on repeated, self-terminating gas-solid reactions, has become the method of choice in semiconductor manufacturing and many other technological areas for depositing thin conformal inorganic material layers for various applications. ALD has been discovered and developed independently, at least twice, under different names: atomic layer epitaxy (ALE) and molecular layering. ALE, dating back to 1974 in Finland, has been commonly known as the origin of ALD, while work done since the 1960s in the Soviet Union under the name "molecular layering" (and sometimes other names) has remained much less known. The virtual project on the history of ALD (VPHA) is a volunteer-based effort with open participation, set up to make the early days of ALD more transparent. In VPHA, started in July 2013, the target is to list, read and comment on all early ALD academic and patent literature up to 1986. VPHA has resulted in two essays and several presentations at international conferences. This paper, based on a poster presentation at the 16th International Conference on Atomic Layer Deposition in Dublin, Ireland, 2016, presents a recommended reading list of early ALD publications, created collectively by the VPHA participants through voting. The list contains 22 publications from Finland, Japan, Soviet Union, United Kingdom, and United States. Up to now, a balanced overview regarding the early history of ALD has been missing; the current list is an attempt to remedy this deficiency. (C) 2016 Author(s).Peer reviewe
Lysozyme responsive spray-dried chitosan particles for early detection of wound infection
Infections are a
severe health issue, and the need for an early
point-of-care diagnostic approach for wound infections is continuously
growing. Lysozyme has shown a great potential as a biomarker for rapid
detection of wound infection. In this study, spray-drying of labeled
and derivatized chitosans was investigated for the production of small
particles responsive to lysozyme. Therefore, various chitosans, differing
in their origin (snow crab, Chionoecetes sp., with
medium and low molecular weight or shrimp) were N-acetylated, labeled with reactive black 5, and tested for solubility
and spray-drying suitability. Reactive black-5-stained N-acetylated chitosan (low molecular weight, origin crab) was successfully
spray-dried, and the obtained particles were characterized regarding
size, ζ potential, and morphology. The particles showed an average
hydrodynamic radius of 612.5 ± 132.8 nm. ζ potential was
measured in the context of a later application as an infection detection
system for wound infections in artificial wound fluid (â6.14
± 0.16 mV) and infected wound fluid (â7.93 ± 1.35
mV). Furthermore, the aggregation behavior and surface structure were
analyzed by using scanning electron microscopy and confocal laser
scanning microscopy revealing spherical-shaped particles with explicit
surface topologies. Spray-dried N-acetylated chitosan
particles showed a 5-fold increase in lysozyme-responsive release
of dyed chitosan fragments due to the enhanced surface area to volume
ratio when compared to non-spray-dried N-acetylated
chitosan flakes. On the basis of these results, the study showed the
improved properties of N-acetylated spray-dried chitosan
particles for future applications for early and rapid infection detection
Community composition and ultrastructure of a Nitrate-dependent anaerobic methane-oxidizing enrichment culture
Methane is a very potent greenhouse gas and can be oxidized aerobically or anaerobically through microbe-mediated processes, thus decreasing methane emissions in the atmosphere. Using a complementary array of methods, including phylogenetic analysis, physiological experiments, and light and electron microscopy techniques (including electron tomography), we investigated the community composition and ultrastructure of a continuous bioreactor enrichment culture, in which anaerobic oxidation of methane (AOM) was coupled to nitrate reduction. A membrane bioreactor was seeded with AOM biomass and continuously fed with excess methane. After 150 days, the bioreactor reached a daily consumption of 10 mmol nitrate · literâ1 · dayâ1. The biomass consisted of aggregates that were dominated by nitrate-dependent anaerobic methane-oxidizing âCandidatus Methanoperedensâ-like archaea (40%) and nitrite-dependent anaerobic methane-oxidizing âCandidatus Methylomirabilisâ-like bacteria (50%). The âCa. Methanoperedensâ spp. were identified by fluorescence in situ hybridization and immunogold localization of the methyl-coenzyme M reductase (Mcr) enzyme, which was located in the cytoplasm. The âCa. Methanoperedensâ sp. aggregates consisted of slightly irregular coccoid cells (âŒ1.5-ÎŒm diameter) which produced extruding tubular structures and putative cell-to-cell contacts among each other. âCa. Methylomirabilisâ sp. bacteria exhibited the polygonal cell shape typical of this genus. In AOM archaea and bacteria, cytochrome c proteins were localized in the cytoplasm and periplasm, respectively, by cytochrome staining. Our results indicate that AOM bacteria and archaea might work closely together in the process of anaerobic methane oxidation, as the bacteria depend on the archaea for nitrite. Future studies will be aimed at elucidating the function of the cell-to-cell interactions in nitrate-dependent AOM