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Immuno-atomic force microscopy of purple membrane

Authors :
Georg Büldt
Cora-Ann Schoenenberger
Daniel J. Müller
Andreas Engel
Source :
Biophysical Journal. 70(4):1796-1802
Publication Year :
1996
Publisher :
Elsevier BV, 1996.

Abstract

The atomic force microscope is a useful tool for imaging native biological structures at high resolution. In analogy to conventional immunolabeling techniques, we have used antibodies directed against the C-terminus of bacteriorhodopsin to distinguish the cytoplasmic and extracellular surface of purple membrane while imaging in buffer solution. At forces > or = 0.8 nN the antibodies were removed by the scanning stylus and the molecular topography of the cytoplasmic purple membrane surface was revealed. When the stylus was retracted, the scanned membrane area was relabeled with antibodies within 10 min. The extracellular surface of purple membrane was imaged at 0.7 nm resolution, exhibiting a major and a minor protrusion per bacteriorhodopsin monomer. As confirmed by immuno-dot blot analysis and sodium dodecyl sulfate-gel electrophoresis, labeling of the purple membrane was not observed if the C-terminus of bacteriorhodopsin was cleaved off by papain.

Details

ISSN :
00063495
Volume :
70
Issue :
4
Database :
OpenAIRE
Journal :
Biophysical Journal
Accession number :
edsair.doi.dedup.....f0828de03093be8da2b8d5e6c9ed61e0
Full Text :
https://doi.org/10.1016/s0006-3495(96)79743-6