Journal of Neural Transmission

, Volume 113, Issue 8, pp 995–1013

Enrichment of integral membrane proteins from small amounts of brain tissue

  • J. Schindler
  • S. Jung
  • G. Niedner-Schatteburg
  • E. Friauf
  • H. G. Nothwang
Article

DOI: 10.1007/s00702-006-0508-4

Cite this article as:
Schindler, J., Jung, S., Niedner-Schatteburg, G. et al. J Neural Transm (2006) 113: 995. doi:10.1007/s00702-006-0508-4

Summary.

Subcellular fractionation represents an essential technique for functional proteome analysis. Recently, we provided a subcellular fractionation protocol for minute amounts of tissue that yielded a nuclear fraction, a membrane and organelle fraction, and a cytosolic fraction. In the current study, we attempted to improve the protocol for the isolation of integral membrane proteins, as these are particularly important for brain function. In the membrane and organelle fraction, we increased the yield of membranes and organelles by about 50% by introducing a single re-extraction step. We then tested two protocols towards their capacity to enrich membrane proteins present in the membrane and organelle fraction. One protocol is based on sequential solubilization using subsequent increases of chaotropic conditions such as urea, thereby partitioning hydrophobic proteins from hydrophilic ones. The alternative protocol applies high-salt and high-pH washes to remove non-membrane proteins. The enrichment of membrane proteins by these procedures, as compared to the original membrane and organelle fraction, was evaluated by 16-BAC-SDS-PAGE followed by mass spectrometry of randomly selected spots. In the original membrane and organelle fraction, 7 of 50 (14%) identified proteins represented integral membrane proteins, and 15 (30%) were peripheral membrane proteins. In the urea-soluble fraction, 4 of 33 (12%) identified proteins represented integral membrane proteins, and 10 (30%) were peripheral membrane proteins. In the high-salt/high-pH resistant sediment, 12 of 45 (27%) identified proteins were integral membrane proteins and 13 (29%) represented peripheral membrane proteins. During the analysis, several proteins involved in neuroexocytosis were detected, including syntaxin, NSF, and Rab3-interaction protein 2. Taken together, differential centrifugation in combination with high-salt and high-pH washes resulted in the highest enrichment of integral membrane proteins and, therefore, represents an adequate technique for region-specific profiling of membrane proteins in the brain.

Keywords: Subcellular prefractionation, membrane proteins, 16-BAC-SDS-PAGE, high-salt/high-pH extraction, sequential solubilization, mass spectrometry, proteomics. 

Abbreviations

CHAPS

3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate

16-BAC

benzyldimethyl-n-hexadecylammonium chloride

SDS

sodium dodecylsulfate

PAGE

polyacrylamide gel electrophoresis

EDTA

ethylenediaminetetraacetic acid

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • J. Schindler
    • 1
  • S. Jung
    • 1
  • G. Niedner-Schatteburg
    • 2
  • E. Friauf
    • 1
  • H. G. Nothwang
    • 1
  1. 1.Abteilung Tierphysiologie, Fachbereich BiologieTechnische Universität KaiserslauternKaiserslauternGermany
  2. 2.Abteilung Clusterchemie, Fachbereich ChemieTechnische Universität KaiserslauternKaiserslauternGermany

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