Structure of the cell wall of the Gram-negative bacterium Proteus vulgaris: II. Distribution of electron density across the wall

摘要: Isolated cell wall preparations of Proteus vulgaris consist arrays two components: the complete (comprising rigid mucopeptide and protein layer or R layer, a lipopolysaccharide lipoprotein layer) thickness 144 A; spheroplast 92 A corresponding to after loss labile layer. The first-order low-angle X-ray reflexion each component is diffuse, but higher orders are sharp. It shown that this occurs if distribution electron density through non-centrosymmetrical occurrence random right- left-handed parallel sheet structures within specimens. interpretation data made in terms centrosymmetrical average structure for which result superimposing units. For both wall, with phases determined by reference micrographs, were found trial-and-error methods. method then described separating superimposed units thus producing whole walls. These closely related observed microscopy, they also make use information contained diffraction patterns. Although distributions so deduced some extent arbitrary, entirely consistent data, far as phase angles may be assigned reflexions, nature such slight distortions would produce images similar those seen microscope embedding sectioning.