Kade Andreas, Vyalikh Denis V, Danzenbächer Steffen, Kummer Kurt, Blüher Anja, Mertig Michael, Lanzara Alessandra, Scholl Andreas, Doran Andrew, Molodtsov Serguei L
Institute of Solid State Physics, Dresden University of Technology, D-01062 Dresden, Germany.
J Phys Chem B. 2007 Dec 6;111(48):13491-8. doi: 10.1021/jp073650z. Epub 2007 Nov 13.
The electronic structure of individual sheets of the bacterial surface protein layer (S layer) of Bacillus sphaericus NCTC 9602 was studied using a photoemission electron microscope (PEEM) operating in near-edge X-ray absorption fine structure spectroscopy mode. The laterally resolved measurements performed at the C 1s, N 1s, and O 1s thresholds on fresh samples revealed characteristic differences compared to the laterally integrated data, where substrate contributions were taken along with the protein signals. During the PEEM experiments an irradiation-induced increase of the C-C bond density at the cost of the densities of the C-O and C-N bonds related to a rearrangement of the contributing atoms of the S layer deposited onto a Si substrate was observed. The critical irradiation doses for the C-O and C-N bond breaking and formation of the new C-C bonds were derived.
利用在近边X射线吸收精细结构光谱模式下运行的光发射电子显微镜（PEEM），研究了球形芽孢杆菌NCTC 9602细菌表面蛋白层（S层）单张薄片的电子结构。在新鲜样品的C 1s、N 1s和O 1s阈值处进行的横向分辨测量显示，与包含底物贡献和蛋白质信号的横向积分数据相比存在特征差异。在PEEM实验过程中，观察到以沉积在硅衬底上的S层贡献原子重排为代价，C-C键密度因辐照而增加，同时C-O键和C-N键密度降低。得出了C-O键和C-N键断裂以及新C-C键形成的临界辐照剂量。
