Q-band electron nuclear double resonance (ENDOR) and X-band EPR of the sulfobetaine 12 heat-treated cytochrome c oxidase complex

Heat treatment of the bovine cytochrome c oxidase complex in the zwitterionic detergent sulfobetaine 12 (SB-12) results in loss of subunit III and the appearance of a type II copper center as characterized by electron paramagnetic resonance (EPR) spectroscopy. Previous authors (Nilsson, T., Copeland, R. A., Smith, P. A., and Chan, S. I. (1988) Biochemistry 27, 8254-8260) have interpreted this type II copper center as a modified version of the CuA site. By using electron nuclear double resonance spectroscopy, it is found that the CuA proton and nitrogen resonances remain present in the SB-12 heat-treated enzyme and that three new nitrogen resonances appear having hyperfine coupling constants consistent with histidine ligation. These hyperfine coupling constants correlate well with those recently found for the CuB histidines from the cytochrome aa3-600 quinol oxidase from Bacillus subtilis (Fann, Y. C., Ahmed, I., Blackburn, N. J., Boswell, J. S., Verkhovskaya, M. L., Hoffman, B. M., and Wikström, M. (1995) Biochemistry 34, 10245-10255). In addition, the total EPR-detectable copper concentration per enzyme molecule approximately doubles upon SB-12 heat treatment. Finally, the observed type II copper EPR spectrum is virtually indistinguishable from the EPR spectrum of CuB of the as-isolated cytochrome bo3 complex from Escherichia coli. These data indicate that the type II copper species that appears results from a breaking of the strong antiferromagnetic coupling of the heme a3-CuB binuclear center

Poeci i uczeni w wierszach okolicznościowych Wincentego Pola

The first part of the paper is dedicated to Wincenty Pol’s occasional poems, dedicated to poets and poetry, and on that basis, it is possible to reconstruct the author’s perception of the situation of poets and poetry, as well as their role in society deprived of political identity. The second area of discussion are Pol’s works, which are addressed to scholars and, at the same time, emphasise the significance of their activity for the spiritual condition of the Poles, and indicate the originality of the poet’s (and an active researcher’s) reflections in relation to individual and collective research initiatives

Integrating Signals from the T-Cell Receptor and the Interleukin-2 Receptor

T cells orchestrate the adaptive immune response, making them targets for immunotherapy. Although immunosuppressive therapies prevent disease progression, they also leave patients susceptible to opportunistic infections. To identify novel drug targets, we established a logical model describing T-cell receptor (TCR) signaling. However, to have a model that is able to predict new therapeutic approaches, the current drug targets must be included. Therefore, as a next step we generated the interleukin-2 receptor (IL-2R) signaling network and developed a tool to merge logical models. For IL-2R signaling, we show that STAT activation is independent of both Src- and PI3-kinases, while ERK activation depends upon both kinases and additionally requires novel PKCs. In addition, our merged model correctly predicted TCR-induced STAT activation. The combined network also allows information transfer from one receptor to add detail to another, thereby predicting that LAT mediates JNK activation in IL-2R signaling. In summary, the merged model not only enables us to unravel potential cross-talk, but it also suggests new experimental designs and provides a critical step towards designing strategies to reprogram T cells

Państwo, gospodarka, społeczeństwo w integrującej się Europie TOM 3

Ze wstępu: "1 maja 2004 przyniesie radykalną zmianą sytuacji dotychczasowych kandydatów do Unii Europejskiej. Z roli aplikanta i petenta przekształcą się we współdecydenta. Już dziś z przyszłymi członkami konsultuje się większość kwestii wymagających strategicznych decyzji. Przez ostatnie dziesięć lat wysiłek polityczny i intelektualny był skierowany na uzyskanie członkostwa Unii, a w ostatnim okresie negocjacji - na osiągnięcie najlepszych według polityków i ekonomistów warunków akcesji. 1 ten etap mamy już za sobą. Pora zacząć patrzeć przed siebie, lecz niejako petent, ale kraj współodpowiedzialny za dalsze funkcjonowanie i rozwój powiększonej Unii. Z tej perspektywy istotnajest analiza gospodarki europejskiej, z którąjuż dziś gospodarka państw kandydackich, także Polski, jest silnie powiązana. Wiedza na ten temat jest uboga i ograniczona do przeglądu bieżących wskaźników makroekonomicznych. Zarówno w ośrodkach rządowych, jak i pozarządowych dominuje podejście analizujące, co z konkretnego wydarzenia w innym kraju wynika dla gospodarki polskiej. Stanowczo nie wystarczy to do pełnienia odpowiedzialnej roli współdecydenta. Potrzebna jest pogłębiona wiedza na temat gospodarki europejskiej jako całości i poszczególnych krajów, a także najważniejszych partnerów handlowych i gospodarczych zjednoczonej Europy. Konieczne są pogłębione prace studialne dotyczące mechanizmów międzynarodowych, gdyż organy unijne będą się zajmować w najbliższych latach dalszym rozwojem europejskiego jednolitego Rynku, rywalizacją gospodarczą z USA i krajami azjatyckimi, liberalizacjąhandlu światowego."(...

The bc 1 complexes of Rhodobacter sphaeroides and Rhodobacter capsulatus

Photosynthetic bacteria offer excellent experimental opportunities to explore both the structure and function of the ubiquinol-cytochrome c oxidoreductase ( bc 1 complex). In both Rhodobacter sphaeroides and Rhodobacter capsulatus , the bc 1 complex functions in both the aerobic respiratory chain and as an essential component of the photosynthetic electron transport chain. Because the bc 1 complex in these organisms can be functionally coupled to the photosynthetic reaction center, flash photolysis can be used to study electron flow through the enzyme and to examine the effects of various amino acid substitutions. During the past several years, numerous mutations have been generated in the cytochrome b subunit, in the Rieske iron-sulfur subunit, and in the cytochrome c 1 subunit. Both site-directed and random mutagenesis procedures have been utilized. Studies of these mutations have identified amino acid residues that are metal ligands, as well as those residues that are at or near either the quinol oxidase (Q o ) site or the quinol reductase (Q i ) site. The postulate that these two Q-sites are located on opposite sides of the membrane is supported by these studies. Current research is directed at exploring the details of the catalytic mechanism, the nature of the subunit interactions, and the assembly of this enzyme.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44795/1/10863_2004_Article_BF00762582.pd