Biology Reference
In-Depth Information
FIGURE 19.2
Determination of the binding site. (A) Competition experiments between Flutax-2 and
MSAs for binding to MTs. Displacement of Flutax-2 (50 nM) fromMT binding sites (50 nM) by
ZMP (black circles), docetaxel (white circles), epothilone A (black squares), and dactylolide
(white squares). Peloruside A (black triangles) was unable to displace Flutax-2 from the
binding site. See
Table 19.2
for the binding constants. The peloruside data were taken
from
Gaitanos et al. (2004)
. The figure was modified from
Field et al. (2012)
with permission
from the publisher. (B) Competition experiments between 1
m
M peloruside and 4
m
M
laulimalide for MTs containing 1
M taxoid binding sites. First section of the graph shows
elution of peloruside and the second elution of laulimalide (mAu
m
milli absorbance units).
Peak at 4.5 min shows peloruside in the supernatant (gray), with none bound to the MTs
in the pellet (black). Peak at 18.8 min shows laulimalide saturation of the pellet with
excess laulimalide in the supernatant, indicating that these two compounds bind the same
site on MTs since excess laulimalide binding prevents peloruside from binding.
ΒΌ
