Average thickness of hepatocyte rough ER membrane

Value 37.5 Å Range: ±0.4 Å
Organism Rat Rattus norvegicus
Reference Mitra K, Ubarretxena-Belandia I, Taguchi T, Warren G, Engelman DM. Modulation of the bilayer thickness of exocytic pathway membranes by membrane proteins rather than cholesterol. Proc Natl Acad Sci U S A. 2004 Mar 23 101(12):4083-8 doi: 10.1073/pnas.0307332101 p. 4085 right column 2nd paragraphPubMed ID15016920
Method Solution x-ray scattering (SXS). "SXS permits direct determination of the distance (d) between the highly electron-dense phosphate groups across the bilayer of membranes in solution (14, 15, 17). A limitation of this technique is that extramembranous protein domains and cell components containing highly electron-dense groups, such as ribosomes, can affect the quality of the scattering data (37)."
Comments "Scattering curves, corrected for background and intensity, were generated in triplicate for all of the treated membranes (Fig. 2A). The curves are characteristic of single bilayer sheets or vesicles, indicating (in addition to EM [Electron Microscopy] visualization) that the bilayer structure of the membranes was retained after protease treatment. The average bilayer thickness, d, can be calculated from the position of the second peak (14) and was found to be highly reproducible for each type of membrane. The second peak in each scattering curve was fitted to a Gaussian distribution to define the maximum. Fig.2B illustrates the change in bilayer thickness [phosphate-to- phosphate (P-P) distance=d] for membranes of the exocytic pathway. Rough ER membranes have a thickness of 37.5±0.4Å. Golgi membranes (39.5±0.4Å) are 2.0±0.8Å thicker than ER membranes. Basolateral plasma membranes (35.6±0.6Å BNID 105822) are 3.9±1.0Å thinner than Golgi membranes whereas apical plasma membranes (42.5±0.3Å) are 6.9±0.9Å thicker than basolateral plasma membranes."
Entered by Uri M
ID 105819