Jon Trullinger has measured a depolymerization rate for f-actin after addition of 5 wt% ethylammonium nitrate (EAN) using the Fluo-STAR Galaxy Plate reader (Ex @ 355 nm and Em @ 405nm)
The decrease in fluorescence intensity of pyrene-labeled actin measured as a function of time post-mixing with EAN shows that EAN has the ability to depolymerize actin. After a 300 sec equilibration time, 10 μL 50 wt% EAN was delivered, via an in-line syringe pump, to a well containing 100 μL 38 μg/ml pyrene-labeled F-actin. Depolymerization is observed as a decrease in fluorescence signal. Data were normalized to the maximum intensity measured prior to depolymerization for each sample. Measurements were done in triplicate. The average normalized intensity values with their standard deviation are shown. OriginPro v7.5 was used to determine the exponential fit parameters (a, b, k) as well as the initial rate of depolymerization.
y = a+be^(-kx)
a=0.02 b=1.51 k=0.0043
Rate = -0.015/sec