Oxoferryl-Porphyrin Radical Catalytic Intermediate in Cytochrome bd Oxidases Protects Cells from Formation of Reactive Oxygen Species

Catalysis and Surface Chemistr

Monitoring global protein thiol-oxidation and protein S-mycothiolation in Mycobacterium smegmatis under hypochlorite stress.

Hillion M, Bernhardt J, Busche T, et al. Monitoring global protein thiol-oxidation and protein S-mycothiolation in Mycobacterium smegmatis under hypochlorite stress. Sci Rep. 2017;7(1): 1195.Mycothiol (MSH) is the major low molecular weight (LMW) thiol in Actinomycetes. Here, we used shotgun proteomics, OxICAT and RNA-seq transcriptomics to analyse protein S-mycothiolation, reversible thiol-oxidations and their impact on gene expression in Mycobacterium smegmatis under hypochlorite stress. In total, 58 S-mycothiolated proteins were identified under NaOCl stress that are involved in energy metabolism, fatty acid and mycolic acid biosynthesis, protein translation, redox regulation and detoxification. Protein S-mycothiolation was accompanied by MSH depletion in the thiol-metabolome. Quantification of the redox state of 1098 Cys residues using OxICAT revealed that 381 Cys residues (33.6%) showed >10% increased oxidations under NaOCl stress, which overlapped with 40 S-mycothiolated Cys-peptides. The absence of MSH resulted in a higher basal oxidation level of 338 Cys residues (41.1%). The RseA and RshA anti-sigma factors and the Zur and NrdR repressors were identified as NaOCl-sensitive proteins and their oxidation resulted in an up-regulation of the SigH, SigE, Zur and NrdR regulons in the RNA-seq transcriptome. In conclusion, we show here that NaOCl stress causes widespread thiol-oxidation including protein S-mycothiolation resulting in induction of antioxidant defense mechanisms in M. smegmatis. Our results further reveal that MSH is important to maintain the reduced state of protein thiols

On the relative role of abiotic and biotic controls in channel network development: insights from scaled tidal flume experiments

Tidal marshes provide highly valued ecosystem services, which depend on variations in the geometric properties of the tidal channel networks dissecting marsh landscapes. The development and evolution of channel network properties are controlled by both abiotic (dynamic flow–landform feedbacks) and biotic processes (e.g. vegetation–flow–landform feedbacks). However, the relative role of biotic and abiotic processes, and under which condition one or the other is more dominant, remains poorly understood. In this study, we investigated the impact of spatio-temporal plant colonization patterns on tidal channel network development through flume experiments. Four scaled experiments mimicking tidal landscape development were conducted in a tidal flume facility: two control experiments without vegetation, a third experiment with hydrochorous vegetation colonization (i.e. seed dispersal via the tidal flow), and a fourth with patchy colonization (i.e. by direct seeding on the sediment bed). Our results show that more dense and efficient channel networks are found in the vegetation experiments, especially in the hydrochorous seeding experiment with slower vegetation colonization. Further, an interdependency between abiotic and biotic controls on channel development can be deduced. Whether biotic factors affect channel network development seems to depend on the force of the hydrodynamic energy and the stage of the system development. Vegetation–flow–landform feedbacks are only dominant in contributing to channel development in places where intermediate hydrodynamic energy levels occur and mainly have an impact during the transition phase from a bare to a vegetated landscape state. Overall, our findings suggest a zonal domination of abiotic processes at the seaward side of intertidal basins, while biotic processes have an additional effect on system development more towards the landward side.</p

A recombinant viral haemorrhagic septicaemia virus glycoprotein expressed in insect cells induces protective immunity in rainbow trout

Viral haemorrhagic septicaemia (VHS) is a fish rhabdovirus infection of world-wide importance. Control policies have been established but the disease still causes heavy losses in fish farming. The development of a recombinant subunit vaccine was initiated to produce a safe and effective vaccine to protect fish against VHS. The VHS virus (VHSV) glycoprotein, which induces neutralizing antibodies in rainbow trout, was chosen for expression in insect cells using a baculovirus vector. The Mr of the recombinant protein estimated by SDS-PAGE was slightly lower than that of the native viral protein. The recombinant protein displayed different degrees of glycosylation and was recognized in ELISA by neutralizing antibodies. It was transported to the plasma membrane of insect cells where its ability to induce membrane fusion was preserved. The efficacy of the recombinant protein as a vaccine was compared with those of an inactivated and an attenuated vaccine. When injected intraperitoneally into rainbow trout, the baculo-virus-encoded protein was shown (i) to induce the synthesis of VHSV-neutralizing antibodies and (ii) to confer protection against virus challenge. Immunization performed by immersion failed. This is the first report of a recombinant vaccine that protects fish against VHSV

Effects of the calcium channel antagonist mibefradil on haemodynamic and morphological parameters in myocardial infarction-induced cardiac failure in rats

Calcium channel antagonists (CCA) have been proposed for the prevention of cardiac events after myocardial infarction (MI). Mibefradil is a CCA featuring a selective blockade of T-type Ca2(+)-channels. The aim of the study was to characterize the effects of mibefradil on haemodynamic and morphological parameters in a model of postMI chronic heart failure and to establish the "therapeutic window" for the start of therapy. MI was induced by permanent ligation of the left coronary artery in male normotensive Wistar rats. Animals were assigned to placebo- or mibefradil-treated (10 mg/kg/day p.o.) groups as follows: (1) sham operation; (2) MI placebo treatment; (3) 7 days preMI start of treatment; (4) 3 h postMI start of treatment; (5) 24 h postMI start of treatment; (6) 3 days postMI start of treatment; (7) 7 days postMI start of treatment. Treatment was continued for 6 weeks postMI. At this time point, mean arterial blood pressure (MAP), heart rate, left ventricular enddiastolic pressure (LVEDP) and contraction force (dP/dtmax) were measured in conscious rats at baseline and after methoxamine (MEX; 0.5-1.0 mg/h i.v.) stimulation to increase afterload. The hearts were subjected to histological determination of infarct size (IS), infarct length (IL), noninfarcted length (NL), left ventricular circumference (LVC), inner LV-diameter (LVD) and septal thickness (ST). Six weeks after MI, MAP was lowered, LVEDP increased and dP/dtmax reduced. Mibefradil treatment increased basal MAP in groups 3-5 compared to the placebo-treated MI group. Under mibefradil, LVEDP was reduced at baseline in groups 3-6 and, after MEX, in all groups. dP/dtmax was increased in groups 3-4 at baseline and after MEX. In the placebo-treated MI group, the infarcted area was 39% of the LV and heart weight, LVD and LVC were increased. Heart weights of mibefradil-treated rats (groups 3-6) did not differ from those of the placebo-treated group. Early onset of treatment with mibefradil reduced IS and IL and increased NL in groups 3-4. LVD and LVC were decreased in group 3 only. ST was increased in groups 3-5. Chronic treatment with mibefradil exerts beneficial actions on cardiac structure and performance in postMI cardiac failure in rats, especially when the onset of treatment is either prior to or within hours after the acute ischemic even

Cardioprotective effects of the Na(+)/H(+)-exchange inhibitor cariporide in infarct-induced heart failure

We investigated the effect of chronic treatment with the new Na(+)/H(+)-exchange inhibitor, cariporide, on cardiac function and remodelling 6 weeks after myocardial infarction (MI) in rats. Treatment with cariporide was commenced either 1 week pre or 30 min, 3 h, 24 h or 7 days after ligation of the left ventricular artery and was continued until haemodynamic parameters were obtained 6 weeks after MI in conscious rats. Compared to sham animals, untreated MI-controls developed pronounced heart failure after 6 weeks. Basal left ventricular end-diastolic pressure (in mmHg) was reduced in the groups in which cariporide was started 1 week pre (16.0+/-1.7) or 30 min (12.5+/-1.1), 3 h (11.8+/-1.0) and 24 h (13.0+/-2.5) after MI compared to untreated MI-controls (22. 4+/-1.5; P <0.01). Basal myocardial contractility (in 1000 mmHg/s) was only increased when treatment was initiated after 30 min (9. 0+/-0.7), 3 h (8.5+/-0.3) and 24 h (8.0+/-0.7) compared to untreated MI-controls (5.8+/-0.7; P <0.05-0.01). Infarct size (in % of left ventricular circumference) was 40.0+/-2.1 in MI-controls and was decreased when treatment was begun after 30 min (32.6+/-2.7) or 3 h (32.4+/-2.3) (P <0.05). In animals, in which cariporide was started 3 h after induction of MI, heart weight/body weight ratio was significantly decreased, indicating reduced cardiac hypertrophy. When treatment started 7 days after MI, cariporide did not exert any beneficial actions on structural and functional cardiac parameters. Our results show for the first time that chronic treatment with the Na(+)/H(+)-exchange inhibitor cariporide engendered marked cardioprotective effects when commenced before and up to 24 h after MI. The optimal time for the start of treatment was between 30 min and 3 h post M

Nucleotide sequence of the bovine viral diarrhoea virus Osloss strain: comparison with related viruses and identification of specific DNA probes in the 5' untranslated region

The nucleotide sequence of the cytopathic Osloss isolate of bovine viral diarrhoea virus (BVDV) was deduced from overlapping cDNA clones and from PCR products. The Osloss genome is an RNA molecule of positive polarity containing 12480 nucleotides and having the capacity to code for a polyprotein of 3975 amino acids. The presence of the previously described internal stop codon in this viral sequence was disproved after direct sequencing of the appropriate PCR-amplified fragment. Except for the previously reported insertion of a sequence coding for a ubiquitin-like protein, the viral genome shares great similarity with those of three other strains of the pestivirus genus. Computer-assisted sequence analyses and comparisons of known pestiviral genomic sequences led us to identify selected PCR primers in the 5' untranslated region. These primers were used successfully to amplify 18 distinct pestivirus isolates and potential DNA probes were noted from the deduced sequences. The possible use of a well conserved 26 base fragment as a diagnostic probe was confirmed in hybridization experiments. The 5' untranslated region was further studied and compared with those of other members of the Flaviviridae family, which includes the flaviviruses and the hepatitis C virus group. These sequence analyses support the possibility of discrimination amongst the closely related ruminant pestiviruses, border disease virus and BVDV

Eureka Verbundprojekt PROMETHEUS. Phase 2 Teilprojekt: Bosch (Hildesheim). Abschlussbericht

Communication between vehicles was the main subject of investigations in the first part of the project. Therefore communication systems for data transmission in the frequency range of 5.8 GHz have been developed as flexible experimentation platforms, tested and provided to partners at research institutes and in the industry in order to implement software and to carry out experiments. The concept of the system is based on the main components PC, protocol processor in the shape of a PC plug-in board microwave transceiver, antennas and synchronisation receiver. By using a TDMA base protocol with fixed allocation of slots the system provides the capacity for 120 vehicles to communicate in a mobile network. The gross data rate used is 1.25 Mbit/s, the capacity of a data paket is 192 bit and the repetition rate is 50 Hz. Such a mobile network needs a central transmitter for the frame synchronisation signal, which has been realized by private UHF mobile radio. Caused by results of frequency discussion, which resulted in the CEPT-Recommendation of 1991, the frequency range of 5.8 GHz is allocated for short range communication between radio beacons and vehicles. Therefore, the activities were shifted to beacon-vehicle communication. In the second part of the project is related to field trials of such a 5.8 GHz communcation system. Beacons were installed in three different test-sites in order to determine the transmission performance under all existing traffic conditions. Results to the main subjects of investigations are based on more than 300 measurement drives. The applied diversity methods have been proven to be very advantageous for the avoidance of interference due to multipath fading. The measured error free communication zones and the transferred data amounts have shown that the 5.8 GHz communication system is very suitable for applications in the field of the new individual traffic management, and that it meets the requirements set by automotive industries and service suppliers. (orig.)Kommunikation zwischen Fahrzeugen war das Hauptthema der Untersuchungen im 1. Teil des Vorhabens. Dazu wurden Kommunikationssysteme fuer Datenuebertragung im Frequenzbereich 5,8 GHz als flexible Experimentierplattform entwickelt, getestet und Kooperationspartnern aus Wissenschaft und Industrie fuer Softwareimplementierungen und Versuche zur Verfuegung gestellt. Das Systemkonzept beruht auf den Hauptkomponenten PC, Protokollprozessor als PC-Einsteckkarte, Mikrowellentransceiver, Antennen und Synchronisationsempfaenger. Mit einem TDMA-Basisprotokoll mit fester Kanalzuweisung koennen bis 120 Fahrzeuge in einem Mobilfunknetz kommunizieren. Die Brutto-Datenrate betraegt 1,25 Mbit/s, die Kapazitaet eines Datenpakets 192 bit und die Wiederholrate 20 Hz. Ein derartiges Mobilfunknetz benoetigt einen zentralen Sender fuer die Synchronisationssignale, der auf einer UHF-Betriebsfunkfrequenz arbeiten kann. Bedingt durch Ergebnisse der Frequenzdiskussion, die gemaess den CEPT-Empfehlungen von 1991 den Frequenzbereich um 5,8 GHz fuer die kurzreichweitige Datenkommunikation zwischen Funkbaken und Fahrzeugen vor sehen, wurden die Aktivitaeten bei 5,8 GHz auf die Baken-Fahrzeug-Kommunikation verlagert. Der zweite Teil des Vorhabens bezieht sich deshalb auf die Feldprobung eines solchen 5,8 GHz-Uebertragungssystem. Drei verschiedene Testgebiete wurden mit Funkbaken ausgeruestet um die Uebertragungseigenschaften unter allen vorkommenden Verkehrsbedingungen bestimmen zu koennen. Die Ergebnisse zu verschiedenen Untersuchungsschwerpunkten stuetzen sich auf mehr als 300 Messfahrten. Die angewendeten Diversityverfahren haben sich zur Vermeidung stoerender Mehrwegeausbreitungseffekte (Fading) als sehr vorteilhaft erwiesen. Die gemessenen stoerungsfreien Kommunikationszonen und die fehlerfrei uebertragenen Datenmengen zeigen, dass das 5,8 GHz-Uebertragungssystem sehr gut fuer die Aufgaben des neuen individuellen Verkehrsmanagements geeignet ist und die Anforderungen von Betreibern und Kraftfahrzeugindustrie erfuellt. (orig.)Available from TIB Hannover: F94B0756+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany); Commission of the European Communities (CEC), Brussels (Belgium)DEGerman