Abstract
We have used a biomembrane force probe decorated with P-selectin to form point attachments with PSGL-1 receptors on a human neutrophil (PMN) in a calcium-containing medium and then to quantify the forces experienced by the attachment during retraction of the PMN at fixed speed. From first touch to final detachment, the typical force history exhibited the following sequence of events: i), an initial linear-elastic displacement of the PMN surface, ii), an abrupt crossover to viscoplastic flow that signaled membrane separation from the interior cytoskeleton and the beginning of a membrane tether, and iii), the final detachment from the probe tip by usually one precipitous step of P-selectin:PSGL-1 dissociation. In this first article I, we focus on the initial elastic response and its termination by membrane separation from the cytoskeleton, initiating tether formation. Quantifying membrane unbinding forces for rates of loading (force/time) in the elastic regime from 240 pN/s to 38,000 pN/s, we discovered that the force distributions agreed well with the theory for kinetically limited failure of a weak bond. The kinetic rate for membrane unbinding was found to increase as an exponential function of the pulling force, characterized by an e-fold scale in force of ∼17 pN and a preexponential factor, or apparent unstressed off rate, of ∼1/s. The rheological properties of tether growth subsequent to the membrane unbinding events are presented in a companion article II.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2288-2298 |
| Number of pages | 11 |
| Journal | Biophysical Journal |
| Volume | 88 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 2005 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biophysics
Cite this
Nano- to microscale dynamics of P-selectin detachment from leukocyte interfaces. I. Membrane separation from the cytoskeleton. / Evans, Evan; Heinrich, Volkmar; Leung, Andrew; Kinoshita, Koji.
In: Biophysical Journal, Vol. 88, No. 3, 03.2005, p. 2288-2298.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Nano- to microscale dynamics of P-selectin detachment from leukocyte interfaces. I. Membrane separation from the cytoskeleton
AU - Evans, Evan
AU - Heinrich, Volkmar
AU - Leung, Andrew
AU - Kinoshita, Koji
PY - 2005/3
Y1 - 2005/3
N2 - We have used a biomembrane force probe decorated with P-selectin to form point attachments with PSGL-1 receptors on a human neutrophil (PMN) in a calcium-containing medium and then to quantify the forces experienced by the attachment during retraction of the PMN at fixed speed. From first touch to final detachment, the typical force history exhibited the following sequence of events: i), an initial linear-elastic displacement of the PMN surface, ii), an abrupt crossover to viscoplastic flow that signaled membrane separation from the interior cytoskeleton and the beginning of a membrane tether, and iii), the final detachment from the probe tip by usually one precipitous step of P-selectin:PSGL-1 dissociation. In this first article I, we focus on the initial elastic response and its termination by membrane separation from the cytoskeleton, initiating tether formation. Quantifying membrane unbinding forces for rates of loading (force/time) in the elastic regime from 240 pN/s to 38,000 pN/s, we discovered that the force distributions agreed well with the theory for kinetically limited failure of a weak bond. The kinetic rate for membrane unbinding was found to increase as an exponential function of the pulling force, characterized by an e-fold scale in force of ∼17 pN and a preexponential factor, or apparent unstressed off rate, of ∼1/s. The rheological properties of tether growth subsequent to the membrane unbinding events are presented in a companion article II.
AB - We have used a biomembrane force probe decorated with P-selectin to form point attachments with PSGL-1 receptors on a human neutrophil (PMN) in a calcium-containing medium and then to quantify the forces experienced by the attachment during retraction of the PMN at fixed speed. From first touch to final detachment, the typical force history exhibited the following sequence of events: i), an initial linear-elastic displacement of the PMN surface, ii), an abrupt crossover to viscoplastic flow that signaled membrane separation from the interior cytoskeleton and the beginning of a membrane tether, and iii), the final detachment from the probe tip by usually one precipitous step of P-selectin:PSGL-1 dissociation. In this first article I, we focus on the initial elastic response and its termination by membrane separation from the cytoskeleton, initiating tether formation. Quantifying membrane unbinding forces for rates of loading (force/time) in the elastic regime from 240 pN/s to 38,000 pN/s, we discovered that the force distributions agreed well with the theory for kinetically limited failure of a weak bond. The kinetic rate for membrane unbinding was found to increase as an exponential function of the pulling force, characterized by an e-fold scale in force of ∼17 pN and a preexponential factor, or apparent unstressed off rate, of ∼1/s. The rheological properties of tether growth subsequent to the membrane unbinding events are presented in a companion article II.
UR - http://www.scopus.com/inward/record.url?scp=21244458900&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=21244458900&partnerID=8YFLogxK
U2 - 10.1529/biophysj.104.051698
DO - 10.1529/biophysj.104.051698
M3 - Article
C2 - 15653718
AN - SCOPUS:21244458900
VL - 88
SP - 2288
EP - 2298
JO - Biophysical Journal
JF - Biophysical Journal
SN - 0006-3495
IS - 3
ER -