Chemistry Reference
In-Depth Information
LFA-1
in Tcell hybridoma
ICAM-1
See [138] for protein immobili-
zation and AFM probe functio-
nalization with cells
Individual LFA-1/ICAM-1 unbinding forces were measured at
various loading rates. Cell adhesion was enhanced by
stimulating the cells with PMA as evidenced by the
larger maximum force required to detach a cell.
The mean unbinding force of single complexes was
about 30 pN for both resting and PMA-stimulated cells
at a rate of 100 pN s
1
and their dynamic response was
similar. Instead, the observed enhanced cell adhesion
induced by PMA arises from a softening of the cell, which
increased the contact area between the interacting
surfaces.
[179]
3A9
LFA-1
in Jurkat T cells
ICAM-1
ICAM-2
See [138] for protein immobili-
zation and AFM probe functio-
nalization with cells
Two-regime dynamic force spectrum for both LFA-1/ICAM-1
and LFA-1/ICAM-2 interactions were observed for loading
rates ranging from 50 to 6
[180]
10
4
pN s
1
. For LFA-1/ICAM-1,
Bell model parameters for resting cells were k
d
(0)
·
0.55 s
1
¼
and x
b
¼
0.26 nm at slow loading rates (outer energy barrier),
and k
d
(0)¼19 s
1
and x
b
¼0.05 nm at fast loading rates
(inner energy barrier). For LFA-1/ICAM-2, Bell model
parameters for resting cells were k
d
(0)¼0.31 s
1
and x
b
¼
0.45 nm at slow loading rates, and k
d
(0)
10 s
1
and x
b
¼
0.16 nm at fast loading rates. For both complexes, Mg
2þ
had a stabilizing effect only at slow loading rates,
whereas PMA had little if no in
¼
uence on the
dissociation reaction.
(Continued)
