High-resolution topography of the S-layer sheath of the archaebacterium Methanospirillum hungatei provided by scanning tunneling microscopy
Autor: | B. L. Blackford, M. H. Jericho, Gordon Southam, Terry J. Beveridge |
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Rok vydání: | 1990 |
Předmět: |
Cell Membrane
Resolution (electron density) Analytical chemistry Bimorph Mineralogy Radius Biology Paracrystalline Archaea Microbiology law.invention Microscopy Electron Microscopy Scanning Tunneling law Transmission electron microscopy Microscopy Graphite Scanning tunneling microscope Molecular Biology Platinum Research Article |
Zdroj: | Scopus-Elsevier |
ISSN: | 1098-5530 0021-9193 |
DOI: | 10.1128/jb.172.11.6589-6595.1990 |
Popis: | The inner and outer surfaces of the sheath of Methanospirillum hungatei GP1 have been imaged for the first time by using a bimorph scanning tunneling microscope (STM) on platinum-coated or uncoated specimens to a nominal resolution in height of ca. 0.4. nm. Unlike more usual types of microscopy (e.g., transmission electron microscopy), STM provided high-resolution topography of the surfaces, giving good depth detail which confirmed the sheath to be a paracrystalline structure possessing minute pores and therefore impervious to solutes possessing a hydrated radius of greater than 0.3 nm. STM also confirmed that the sheath consisted of a series of stacked hoops approximately 2.5 nm wide which were the remnants of the sheath after treatment with 2% (wt/vol) sodium dodecyl sulfate-2% (vol/vol) beta-mercaptoethanol (pH 9.0). No topographical infrastructure could be seen on the sides of the hoops. This research required the development of a new long-range STM capable of detecting small particles such as bacteria on graphite surfaces as well as a new "hopping" STM mode which did not deform the poorly conducting bacterial surface during high-resolution topographical analysis. |
Databáze: | OpenAIRE |
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