FASEB J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
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 Abbott, A. J.
Right arrow Articles by Nelsestuen, G. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Abbott, A. J.
Right arrow Articles by Nelsestuen, G. L.

The FASEB Journal, Vol 2, 2858-2866, Copyright © 1988 by The Federation of American Societies for Experimental Biology

REVIEWS

The collisional limit: an important consideration for membrane- associated enzymes and receptors

AJ Abbott and GL Nelsestuen
Department of Biochemistry, University of Minnesota, St. Paul 55108.

Because of the proximity of many bound receptors or enzymes, a membrane surface may become uniformly reactive so that every collision between a ligand and the membrane particle results in a binding or catalytic event. At this limit (the collisional limit), the reaction rate depends on membrane particle (cell) concentration and is independent of receptor concentration. Many receptor systems display properties that satisfy the requirements of a collisionally limited reaction. These include the presence of many receptors per cell. The filling of only a few of these receptors often generates the maximum cellular response, and the remaining receptors have been referred to as spare receptors. However, many receptors are needed to produce the collisional limit, and spare receptors may represent nature's evolution toward a reaction that provides the maximum rate as well as the maximum sensitivity to a ligand. Since receptors or enzymes provided on small membrane fragments will not function at the collisional limit, properties of reconstituted enzymes or receptors may not be extrapolated to the physiological situation. The use of normal bimolecular kinetic or equilibrium equations is inappropriate for reactions limited by collision and can give unusual results that lead to inappropriate conclusions. Determination of whether the collisional limit applies to a membrane- bound system is important for understanding its properties and those of the physiological circumstance.


This article has been cited by other articles:


Home page
 Pharmacol. Rev.Home page
A. Christopoulos and T. Kenakin
G Protein-Coupled Receptor Allosterism and Complexing
Pharmacol. Rev., June 1, 2002; 54(2): 323 - 374.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
G. L. Nelsestuen, M. Stone, M. B. Martinez, S. B. Harvey, D. Foster, and W. Kisiel
Elevated Function of Blood Clotting Factor VIIa Mutants That Have Enhanced Affinity for Membranes. BEHAVIOR IN A DIFFUSION-LIMITED REACTION
J. Biol. Chem., October 19, 2001; 276(43): 39825 - 39831.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1988 by The Federation of American Societies for Experimental Biology.