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Pascal,<br>
<br>
You can determine the vbar of your RNA using a sedimentation equilibrium
experiment to determine the buoyant molar mass. Since you know the Mw of
the RNA you can solve for the vbar. A sedimentation velocity
titration should be easily performed since the RNA has a signal
approximately 20X the protein signal. Consequently, by monitoring 260 or
250nm you can follow the changes in the s value of the RNA as it binds
protein with minimal optical contribution from the protein. We did this
using both band and boundary velocity for a regulatory protein binding to
operator/promoter DNA (Biochemistry <b>40</b>, 13378-13389, 2001).
I submitted error corrections for eqns. 1 and 2 but they have not
appeared yet. This gives me an opportunity to correct the errors.
Eq.1: M should be to the 2/3 power and in eq.2: the hydration friction
term should be [(vbar2+vbar1xdelta)/vbar2] raised to the 1/3
power. <x-tab> </x-tab><br>
<x-tab> </x-tab>Good luck
with your future experiments.<br>
<br>
<br>
<font face="Times New Roman, Times">Jacob Lebowitz, PhD <br>
Molecular Interactions Resource <br>
Division of Bioengineering and Physical Science, ORS <br>
National Institutes of Health <br>
Mail: Bldg. 13 Rm. 3N17<br>
Office Bldg. 13 Rm. 3E49<br>
13 South Drive <br>
Bethesda, MD 20892 - 5766 <br>
Tel: (301) 435-1955 <br>
Fax: (301) 480-1242<br>
</font>email: lebowitz@helix.nih.gov<br>
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