[RASMB] Weak association?

[mitrana at mail.utexas.edu]

You can try to fit the data globally using the program SEDANAL. You  
can specify a hydrodynamic non-ideality (ks) value of 0.009 ml/mg for  
a globular protein and see if the data is well described by a 1  
component model or a monomer-dimer model.
Mitra


Quoting "Leech, AP" <apl3 at york.ac.uk>:

> Hello all,
>
> I have done some SV runs at various concentrations 0.3-10 mg/ml on
> a protein (~14 ka) and the sedimentation coefficient appears to
> remain constant (about 1.58). I had expected it to drop slightly at
> higher concentrations, and so I suspect a weak self association.
> Buffer is NaCl/Tris.
>
> Is it reasonable to try and estimate an association coefficient
> from this sort of data, and what is the best way to do it? (Even
> a lower limit would be acceptable, as the intent is to show that
> dimerisation is not significant).
>
> I'm working my way through Gilbert & Gilbert at the moment (Meth.
> Enzymol vol 27, p273) but is there perhaps something more in the
> "global analysis" line?
>
> All comments appreciated,
>
> Andrew
>
> -- 
> Dr Andrew Leech                   *  Laboratory Manager
> Technology Facility               *  Molecular Interactions Laboratory
> Department of Biology (Area 15)   *  Tel   : +44 (0)1904 328723
> University of York                *  Fax   : +44 (0)1904 328804
> PO Box 373,  York  YO10 5YW       *  Email : apl3 at york.ac.uk
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