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Biomedical subjects

D Naumann

Publications and source records attributed to D Naumann.

57 records · Page 4Linked to original sources

Scrapie-infected cells, isolated prions, and recombinant prion protein: a comparative study.

Fourier -transform infrared microscopic spectra of scrapie-infected nervous tissue measured at high spatial resolution (approximately 6 microm) were compared with those obtained from the purified, partly proteinase K digested scrapie isoform of the prion protein isolated from nervous tissue of hamsters infected with the same scrapie strain (263K) to elucidate similarities/dissimilarities between prion structure investigated in situ and ex vivo. A further comparison is drawn to the recombinant Syrian hamster prion protein SHaPrP(90-232) after in vitro conformational transition from the predominantly alpha-helical isoform to beta-sheet-rich structures. It is shown that prion protein structure can be investigated within tissue and that detectability of regions with elevated beta-sheet content as observed in microspectra of prion-infected tissue strongly depends on spatial resolution of the experiment.

Animals↗

Conformational and topological aspects of the three-dimensional architecture of bacterial peptidoglycan.

An atomic model of the conformation of peptidoglycan was taken as the basis for an analysis of packing patterns of the peptidoglycan strands in two- and three-dimensional arrangements. For the sake of clarity, glycan strands were approximated by cylindrical rods around which a continuous helix of possible peptide cross-linkage sites was arranged. Using the packing patterns obtained, several important properties of the murein network could be explained. These include variations in the degree of cross-linking in Gram-negative and Gram-positive bacteria and an estimation of the number of peptide monomers, di/trimers and oligomers present. Furthermore, our model is compatible with the well known flexibility of the murein fabric and the distinct elastic properties of the cell wall in gram-positive cocci and rod-shaped bacteria.

Bacteria↗