[RASMB] AUC of RNA and RNA-proteins complexes

[pascal egea]

Greetings,
I am trying to do some AUC on a small synthetic RNA fragment (49
nucleotides) and its complex with proteins by looking first at its
sedimentation coefficient by velocity sedimentation.
Does anybody have some experience about that? I heard that AUC on nucleic
acids is hell and I would like to know if there are some good reference
papers about this specific type of macromolecular systems?
My actual S is about 3 S assuming a 0.55 ml/g V-bar (it seems very huge to
me)...?
what are the v-bar for RNA molecules? and what reasonnable value of S should
I expect for a monomeric RNA piece of 49 nucleotide mainly folded as double
stranded loop.

Thank you in advance for your help

Pascal Egea
UCSF
Department of Biophysics and Biochemistry