Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Determination of Molecular Motion in Membranes Using Periodic Pattern Photobleaching

Barton A. Smith and Harden M. McConnell
Proceedings of the National Academy of Sciences of the United States of America
Vol. 75, No. 6 (Jun., 1978), pp. 2759-2763
Stable URL: http://www.jstor.org/stable/68322
Page Count: 5
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Determination of Molecular Motion in Membranes Using Periodic Pattern Photobleaching
Preview not available

Abstract

The lateral diffusion of a fluorescent phospholipid probe in oriented multibilayers of dimyristoylphosphatidylcholine has been measured by observing the redistribution of fluorescence after photobleaching of the membranes in a periodic pattern of parallel stripes. The diffusion constant D of the fluorescent lipid was found to vary between 1.5 × 10-11 cm2/sec at 9.6 degrees and 2.0 × 10-10 at 22.5 degrees in the monoclinic phase. Preliminary studies of dipalmitoylphosphatidylcholine liposomes in the Lβ ′ and Pβ ′ phases yielded diffusion constants of the order of 10-11 cm2/sec. These data are relevant to earlier discussions of the rate of complement activation by hapten-sensitized liposomal membranes [Brulet, P. and McConnell, H. M. (1976) Proc. Natl. Acad. Sci. USA 73, 2977-2981; Parce, J. W., Henry, N. and McConnell, H. M. (1978) Proc. Natl. Acad. Sci. USA 75, 1515-1518]. We have also used this method to study the motion of fluorescent antibodies bound to murine EL-4 tumor cells. Pattern photobleaching techniques have the advantages that cellular or liposomal translation has no major adverse effect on the measurements, that certain nondiffusive motions can be detected and characterized, and that diffusive or other motions can be recorded photographically.

Page Thumbnails

  • Thumbnail: Page 
2759
    2759
  • Thumbnail: Page 
2760
    2760
  • Thumbnail: Page 
2761
    2761
  • Thumbnail: Page 
2762
    2762
  • Thumbnail: Page 
2763
    2763