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<DIV><FONT face=Arial size=2>Dear John Doran and
Colleagues,</FONT></DIV>
<DIV><FONT face=Arial size=2>concerning your membrane protein mail,
the reader can hardly judge if he don't know the density of
the</FONT></DIV>
<DIV><FONT face=Arial size=2>detergent ( or 1/ density =Vbar) you
used to make the detergent gravitational transparet.If you used
D<FONT size=1>2</FONT>O </FONT></DIV>
<DIV><FONT face=Arial size=2><FONT size=3>
<DIV><FONT face=Arial size=2>or <FONT size=3><FONT size=2>D2</FONT><SPAN
style="FONT-SIZE: 14pt; FONT-FAMILY: 'Times New Roman'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: DE; mso-fareast-language: DE; mso-bidi-language: AR-SA"><SUP><FONT
size=1><FONT size=2>1</FONT>8</FONT></SUP></SPAN>O, </FONT><FONT size=2>(lower
then the highest concentration of both
mentionated) it seems that you can use Tanfords
<DIV><FONT size=2> mode (Ref. 1 of the attached paper), and I
don't see why it shoud't functionate!. </FONT></DIV>
<DIV><FONT size=2>The Probleme is different if you use a densifier
like p. E. sucrose, because in such case the preferential solvation, what
means ,water between the 1)protein and 2)the detergent, both will achieve a
too low density value of the complex.We calculate see Abstract
about + / - 15% error of the Mw.</FONT></DIV>
<DIV>I attached a BBA 1462 (2000) paper from where you can achieve
more information.</DIV>
<DIV>yours ariel</DIV>
<DIV><A href="mailto:ariel.lustig@bluewin.ch">ariel.lustig@bluewin.ch</A></DIV>
<DIV> </DIV></FONT></FONT></DIV>
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