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A co-ordinated series of field experiments were conducted to consider the effects of elevated UV-B radiation applied directly to decomposing plant litter. Betula pubescens was decomposed under ambient and elevated UV-B (simulating a 15% ozone depletion) using outdoor irradiation facilities at Adventdalen, Norway (78° N), Abisko, Sweden (68° N), Amsterdam, The Netherlands (52° N,) and Patras, Greec

The EPR and thermodynamic properties of semiquinone (SQ) species stabilized by mammalian succinate:quinone reductase (SQR) in situ in the mitochondrial membrane and in the isolated enzyme have been well documented. The equivalent semiquinones in bacterial membranes have not yet been characterized, either in SQR or quinol:fumarate reductase (QFR) in situ. In this work, we describe an EPR-detectable

Nitric oxide (NO) can modulate both tumor growth and antitumor immune responses. In order to elucidate the mechanism of curative therapeutic immunization with IFNgamma-producing glioma cells, we examined the expression of inducible nitric oxide synthase (iNOS) in tissue sections from immunized animals. There was a significantly enhanced iNOS expression both intratumorally and at the immunization s

Leukotriene ( LT) A(4) hydrolase is a bifunctional zinc metalloenzyme, which converts LTA(4) into the neutrophil chemoattractant LTB4 and also exhibits an anion-dependent aminopeptidase activity. In the x-ray crystal structure of LTA(4) hydrolase, Arg(563) and Lys(565) are found at the entrance of the active center. Here we report that replacement of Arg(563), but not Lys(565), leads to complete a

The catalytic properties of the rotenone-sensitive NADH:ubiquinone reductase (Complex I) in bovine heart submitochondrial particles and in inside-out vesicles derived from Paracoccus denitrificans and Rhodobacter capsulatus were compared. The prokaryotic enzymes catalyze the NADH oxidase and NADH:quinone reductase reactions with similar kinetic parameters as those for the mammalian Complex I, exce

β-Alanine synthase (βAS), which is a dizinc metalloenzyme, catalyzes the irreversible hydrolysis of N-carbamyl-β-alanine (NCβA) to β-alanine. This enzyme has potential applications for β-amino acid production. Understanding the reaction mechanism and selectivity of βAS at atomic details can help design and engineer the enzyme for cascade biocatalysis. Here, the protonation states of two conserved

Electrification of energy demand is seen as one of the key elements of energy transition toward decarbonisation. E-mobility is one main side of the electrification process, and it is considered as a crucial way to reduce the emissions of the transport sector. A core element for a widespread adoption of electric vehicles (EVs) is the deployment of the charging infrastructure, and installing a micro

Secondary organic aerosol (SOA) plays a significant role in climate change by altering the global atmospheric radiation budget. Biogenic volatile organic compounds (BVOCs) are major sources for the formation of SOA. Their relationship is critical to understand the continental biosphere-aerosol-cloud-climate (COBACC) feedback mechanism but receives less attention in previous studies. In this study,

Formerly widely distributed throughout Europe, the great snipe (Gallinago media) – a medium-sized wader species – has experienced an important decline in the last century, mainly driven by habitat loss. Remaining population are now restricted to eastern Europe and Scandinavia and the species is considered endangered. The great snipe (Gallinago media) is a food specialist, feeding almost exclusivel

The maximum light use efficiency (LUE = gross primary production (GPP)/absorbed photosynthetic photon flux density (aPPFD)) of plant canopies has been reported to vary spatially and some of this variation has previously been attributed to plant species differences. The canopy nitrogen concentration [N] can potentially explain some of this spatial variation. However, the current paradigm of the N-e

Popular Abstract in Swedish Komplementsystemet är ett system bestående av cirka 35 proteiner i blodet och på cellytor, som ingår i kroppens medfödda immunförsvar. Det är ett mycket viktigt men också explosivt system, potentiellt skadligt för kroppens egna celler, som kräver strikt reglering. Denna avhandlings huvudaktör, C4b-bindande protein (C4BP), nedreglerar komplementsystemet. C4BP har en ovanThe subject of this thesis is plasma protein C4b-binding protein (C4BP). C4BP is an important regulator of the classical pathway of the complement system, a cascade-like system comprised of over 35 proteins, which partakes in the defence against micro-organisms and is involved of clearance of immune-complexes and apoptotic cells. C4BP contains two different types of subunits, seven identical alfa-

What is the significance of a place at the seashore? What kind of a sense of place does a place by the seashore constitute in the absence of any kind of monumental structures? Today, it is obvious within the archaeological domain that archaeological material culture is not only functional, but also acts as a metaphor for people’s self-perception. In this article, my assumption is that the differen

The specific insertion of a divalent metal ion into tetrapyrrole macrocycles is catalyzed by a group of enzymes called chelatases. Distortion of the tetrapyrrole has been proposed to be an important component of the mechanism of metallation. We present the structures of two different inhibitor complexes: (1) N-methylmesoporphyrin (N-MeMP) with the His183Ala variant of Bacillus subtilis ferrochelat

Ribonucleotide reductases (RNRs) catalyze the reduction of ribonucleotides to deoxyribonucleotides, the building blocks for DNA synthesis, and are found in all but a few organisms. RNRs use radical chemistry to catalyze the reduction reaction. Despite RNR having evolved several mechanisms for generation of different kinds of essential radicals across a large evolutionary time frame, this initial r