ISSN:
1432-1424
Keywords:
Intercellular communication
;
Membrane channel structure
;
Image analysis
;
Molecular recognition
;
Cryoelectron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract Gap junctions, collections of membrane channels responsible for intercellular communication, contain two paired hemichannels (also called connexons). We have investigated conditions for splitting the membrane pair using urea. We have developed a protocol which consistently splits the gap junction samples with 60–90% efficiency. Our results indicate that hydrophobic forces are important in holding the two connexons together but that Ca2+ ions are also important in the assembly of the membrane pair. Greater yields and better structural integrity of split junctions were obtained with a starting preparation of gap junctions which had been detergent treated. Image analysis of edge views of single connexon layers reveal an asymmetry in the appearance of the cytoplasmic and extracellular surface. Cryo-electron microscopy and image analysis of split junctions show that the packing and structural detail of membranes containing arrays of single connexons are the same as for intact junctions, and that the urea treatment causes no gross structural changes in the connexon assembly.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00232677
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