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<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;">Hi Ron-<br>
In addition to sedimenting different total concentrations at different rotor speeds, you need to sediment different molar ratios of the components (at different rotor speeds). Also, you will need to sediment each component alone in order to determine whether
self-association needs to be considered. <br>
All of this should be done in conjunction with sedimentation velocity analysis. The biggest hurdle in this work typically is determining the stoichiometries of assembly. Sometimes it is impossible to establish the stoichiometries uniquely (several will fit
the data equally well). This may be an appropriate project for the genetic algorithm approach available in UltraScan, and definitely will require the use of programs that combine equilbrium and velocity analyses.<br>
Best wishes,<br>
Tom <br>
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<div style="direction: ltr;" id="divRpF911963"><font color="#000000" size="2" face="Tahoma"><b>From:</b> rasmb-bounces@list.rasmb.org [rasmb-bounces@list.rasmb.org] on behalf of Toth IV, Ronald T [Toth.Ronald@ku.edu]<br>
<b>Sent:</b> Wednesday, January 22, 2014 4:35 PM<br>
<b>To:</b> rasmb@rasmb.org<br>
<b>Subject:</b> [RASMB] Characterizing hetero association via sedimentation equilibrium<br>
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<div style="direction:ltr; font-family:Tahoma; color:#000000; font-size:10pt">Hello Members!
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<div>Thank you all for your help in the past! I have a new question!<br>
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<div>Given that the standard procedure for characterizing a self association with sedimentation equilibrium is to sediment three different concentrations at three different rotor speeds, my question is this: Is there a standard procedure for characterizing
a hetero association?</div>
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<div><span style="font-size:10pt">Should I sediment three samples at different total protein concentration while keeping the molar ratio of antibody to ligand constant? Should I sediment three different molar ratios of antibody to ligand?</span></div>
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<div><span style="font-size:10pt">Some further information: We have an antibody-ligand system, and the ligand is 20 kDa. The ligand binds in the Fc region, so it's not necessarily limited to a divalent interaction.</span></div>
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<div><span style="font-size:10pt">Thanks again for your help I really appreciate it!</span></div>
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<div style="margin:0px"><font size="3" face="Times New Roman,serif"><span style="font-size:12pt"><font size="2" face="Tahoma,sans-serif"><span style="font-size:10pt">- Ronald Toth</span></font></span></font></div>
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<div style="margin:0px"><font size="3" face="Times New Roman,serif"><span style="font-size:12pt"><font size="2" face="Tahoma,sans-serif"><span style="font-size:10pt">Post Doctoral Researcher</span></font></span></font></div>
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<div style="margin:0px"><font size="3" face="Times New Roman,serif"><span style="font-size:12pt"><font size="2" face="Tahoma,sans-serif"><span style="font-size:10pt">Macromolecule and Vaccine Stabilization Center</span></font></span></font></div>
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<div style="margin:0px"><font size="3" face="Times New Roman,serif"><span style="font-size:12pt"><font size="2" face="Tahoma,sans-serif"><span style="font-size:10pt">University of Kansas</span></font></span></font></div>
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