[RASMB] density matching ASB-14

[Borries Demeler]

> 
> Dear All,
> 
> I will have to run an SV experiment in the presence of the detergent 
> ASB-14 at 0.5%. It is a solid and I wondered if anyone has any 
> information on the density of it in solution so I can do density 
> matching? Or is it not that easy in this case?
> 
> The aim of the experiment is to get the oligomeric state of a membrane 
> protein.
> 
> If the density is unavailable, any suggestion on how to most easily 
> approach the problem would be highly welcome. I fear to determine the 
> density by running ASB-14 in H20/D20 mixes might fail as it does not 
> seem to absorb much at any wavelength (is interference sensitive enough?).
> 
> Also, I have not entirely understood how to account for the influence 
> detergents have on the viscosity. I should be able to organise access to 
> an Anton-Paar densitometer, but I don't think there is a viscosimeter 
> that I could use.
> 
> Is SE inavoidable?
> 
> For more information on the detergent, if that helps, here is the full 
> name and link to Sigma:
> Amidosulfobetaine-14,3-[N,N-Dimethyl(3-myristoylaminopropyl)ammonio]propanesulfonate.
> http://www.sigmaaldrich.com/catalog/ProductDetail.do?D7=0&N5=SEARCH_CONCAT_PNO|BRAND_KEY&N4=A1346|SIGMA&N25=0&QS=ON&F=SPEC
> 
> Literature recommendations (preferably overviews and experimental 
> methods) are also welcome.
> 
> Thank you very much in advance.
> 
> Regards
> Tina

Hi Tina,

there is a nice discussion on the study of membrane proteins by
sedimentation equilibrium in Current Protocols in Protein
Sciences by Karen Fleming that may prove helpful. See:

Karen G. Fleming, Determination of Membrane Protein Molecular Weight
Using Sedimentation Equilibrium Analytical Ultracentrifugation.
2008 (53)7.12

Sorry, I don't have any info on the properties of ABS-14.

-b.