help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Biophys. J. BioFAST: First Published November 3, 2006. doi:10.1529/biophysj.106.089649
© 2006 by the Biophysical Society.

A more recent version of this article appeared on February 1, 2007.
This Article
Right arrow Full Text (Rapid PDF)
Right arrow All Versions of this Article:
biophysj.106.089649v1
92/3/1022    most recent
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zhu, D.-M.
Right arrow Articles by Golan, D. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zhu, D.-M.
Right arrow Articles by Golan, D. E.

CELL BIOPHYSICS

Analysis of Two-Dimensional Dissociation Constant of Laterally Mobile Cell Adhesion Molecules

De-Min Zhu 1, Michael L. Dustin 2, Christopher W. Cairo 3 and David E. Golan 3*

1 Merck Research Laboratories
2 NYU School of Medicine
3 Harvard Medical School

* To whom correspondence should be addressed. E-mail: dgolan{at}hms.harvard.edu.

Submitted on May 23, 2006
Revised on July 13, 2006
Accepted on 2 October 2006


  Abstract
We formulate a general analysis to determine the two-dimensional dissociation constant (2D Kd), and use this method to study the interaction of CD2-expressing T cells with glass-supported planar bilayers containing fluorescently labeled CD58, a CD2 counter-receptor. Both CD2 and CD58 are laterally mobile in their respective membranes. Adhesion is indicated by accumulation of CD2 and CD58 in the cell-bilayer contact area; adhesion molecule density and contact area size attain equilibrium within 40 minutes. The standard (Scatchard) analysis of solution-phase binding is not applicable to the case of laterally mobile adhesion molecules due to the dynamic nature of the interaction. We derive a new binding equation, B / F = [(Nt x f) / (Kd x Scell)] - [(B x p) / Kd], where B and F are bound and free CD58 density in the contact area, respectively, Nt is CD2 molecule number per cell, f is CD2 fractional mobility, Scell is cell surface area, and p is the ratio of contact area at equilibrium to Scell. We use this analysis to determine that the 2D Kd for CD2-CD58 is 5.4-7.6 molecules/µm2. 2D Kd analysis provides a general and quantitative measure of the mechanisms regulating cell-cell adhesion.

Key Words: CD2, CD58, T-lymphocytes, contact area, receptor-ligand interaction theory, two-dimensional affinity




This article has been cited by other articles:


Home page
 Biophys. JHome page
M. Saitakis, A. Dellaporta, and E. Gizeli
Measurement of Two-Dimensional Binding Constants between Cell-Bound Major Histocompatibility Complex and Immobilized Antibodies with an Acoustic Biosensor
Biophys. J., November 15, 2008; 95(10): 4963 - 4971.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
T. P. Tolentino, J. Wu, V. I. Zarnitsyna, Y. Fang, M. L. Dustin, and C. Zhu
Measuring Diffusion and Binding Kinetics by Contact Area FRAP
Biophys. J., July 15, 2008; 95(2): 920 - 930.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Copyright © 2006 by the Biophysical Society.