[RASMB] Help with determining the presence of dimer in a sample

[rmf]

Hi there,

I am relatively new to the field of analytical ultracentrifuge and in 
particular 
to sedimentation equilibrium and I was wondering if anyone has time to 
answer a few of my questions.

I have been performed an sedimentation equilibrium run a carbohydrate 
binding protein .

I have run three samples; the native protein, the protein +triose and 
protein + hexose. I used six-channel cells using concentrations of O.D. 3, 
6 and 8 (measured at 280nm) and scanned (using absorbance - 280 nm) 
after running the cells at 25,000 ; 35,000 and 45,000 rpm for 24 hours 
each.

We believe the that protein may for a dimer in the third sample where it 
binds to hexose.

Does anyone have a suggestion on the best method or technique or 
model for determining if a dimer is present and any other information I 
can possibly obtain from these sample (ie. homogeneity with respect to 
Mw, association constants, etc.) ?

Or suggestions to experimental design?

 I am currently using Ultrascan 6.2 for data analysis


Thanks, if  you can provide me with any help or tips or if you point me to 
good references.

Ron Finn
Department of Biochemistry/Microbiology
University of Victoria

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