排序方式: 共有123条查询结果,搜索用时 15 毫秒
121.
J. Chwiej A. Sarapata K. Janeczko Z. Stegowski K. Appel Z. Setkowicz 《Journal of biological inorganic chemistry》2011,16(2):275-283
This paper describes the results of the application of X-ray fluorescence microscopy to the qualitative, topographic and quantitative
elemental analysis of nervous tissue from rats with neocortical brain injury. The tissue samples were analyzed with a 15 μm
beam defined by the size of the polycapillary focus. Raster scanning of the samples generated 2D cartographies, revealing
the distributions of elements such as P, S, Cl, K, Ca, Fe, Cu, and Zn. Special emphasis was placed on the analysis of the
areas neighboring the lesion site and the hippocampal formation tissue. The results obtained for rats with mechanical brain
injuries were compared with those recorded for controls and animals with pilocarpine-induced seizures. There were no significant
differences in the elemental compositions of gray and white matter between injured and uninjured brain hemispheres. A higher
level of Ca was observed in the gray matter of both of the hemispheres in brains with neocortical injuries. A similar relation
was noticed for Fe in the white matter. A comparative study of hippocampal formation tissue showed a statistically significant
decrease in the mass per unit area of P in the dentate gyrus (DG) and the hilus (H) of DG for animals with brain lesions in
comparison with the control group. Analogous relations were found for Cu in the DG and Zn in sector 3 of Ammon’s horn (CA3)
and the DG. It is important to note that identical changes in the same areas were observed for animals with pilocarpine-induced
seizures in our previous study. 相似文献
122.
123.
ukasz Mazurek Dmitry Ghilarov Elizabeth Michalczyk Zuzanna Pakosz Mikhail Metelev Wojciech Czyszczo Karolina Wawro Iraj Behroz Svetlana Dubiley Roderich D Süssmuth Jonathan G Heddle 《Nucleic acids research》2021,49(3):1581
DNA gyrase, a type II topoisomerase found predominantly in bacteria, is the target for a variety of ‘poisons’, namely natural product toxins (e.g. albicidin, microcin B17) and clinically important synthetic molecules (e.g. fluoroquinolones). Resistance to both groups can be mediated by pentapeptide repeat proteins (PRPs). Despite long-term studies, the mechanism of action of these protective PRPs is not known. We show that a PRP, QnrB1 provides specific protection against fluoroquinolones, which strictly requires ATP hydrolysis by gyrase. QnrB1 binds to the GyrB protein and stimulates ATPase activity of the isolated N-terminal ATPase domain of GyrB (GyrB43). We probed the QnrB1 binding site using site-specific incorporation of a photoreactive amino acid and mapped the crosslinks to the GyrB43 protein. We propose a model in which QnrB1 binding allosterically promotes dissociation of the fluoroquinolone molecule from the cleavage complex. 相似文献