Not quite correct, look into Blue Native PAGE. There you can seperate
natively by mass.
Jürgen
......................
Jürgen Bosch
Johns Hopkins Bloomberg School of Public Health
Department of Biochemistry & Molecular Biology
Johns Hopkins Malaria Research Institute
615 North Wolfe Street, W8708
Baltimore, MD 21205
Phone: +1-410-614-4742
Lab: +1-410-614-4894
Fax: +1-410-955-3655
http://web.mac.com/bosch_lab/
On May 19, 2010, at 1:31, Maia Cherney <[log in to unmask]> wrote:
> Dear Jacob, I offer you my opinion.
> Are you talking about electrophoresis? As far as I know it does not
> work
> for the mass. The velocity of a protein depends on the charge at a
> particular pH, the mass and shape of molecules etc. It's very
> difficult
> to take all these things into consideration. Otherwise this would be a
> very convenient method, much easier than the analytical centrifugation
> or gel-filtration that are usually used. However, electrophoresis
> does
> not work for mass determination. Besides, complex formation hugely
> depends on the protein concentration. If you dilute your mixture, your
> complexes might dissociate. There is equilibrium constant between
> different types of complexes.
>
> Maia
>
>
> Jacob Keller wrote:
>> Dear Crystallographers,
>>
>> I am trying to optimize a native gel experiment of a two-protein
>> complex, running the smallest-detectable amount of protein
>> component A
>> with varying amounts of component B.
>>
>> MW Charge MW/Charge
>> A 22 -5 -4308
>> B 17 -24 -702
>>
>> This experiment is partly to determine stoichiometry, but also to
>> determine roughly the strength of the interaction.
>>
>> B definitely runs much faster than A alone, as predicted, but I am
>> wondering what to expect with various oligomers. Should ABB run
>> faster
>> or slower than AB? What about AABB? Theoretically, AA should
>> certainly
>> run slower than A, and BB slower than B, simply because the
>> mass/charge ratio is the same, but the overall mass is greater. But
>> what happens when you have AAB, for example? There must be an
>> equation
>> relating the mass/charge and mass (and perhaps gel percentage) to the
>> speed traveled in the gel--but what is the equation?
>>
>> Thanks for your consideration,
>>
>> Jacob
>>
>> *******************************************
>> Jacob Pearson Keller
>> Northwestern University
>> Medical Scientist Training Program
>> Dallos Laboratory
>> F. Searle 1-240
>> 2240 Campus Drive
>> Evanston IL 60208
>> lab: 847.491.2438
>> cel: 773.608.9185
>> email: [log in to unmask]
>> *******************************************
>>
>>
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