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<BODY style="MARGIN: 4px 4px 1px; FONT: 10pt Tahoma">vanHolde & Baldwin (JPhysChem 62, 1958 paper) measured D for sucrose from Archibald or approach to equilibrium experiment. Got 4.93 to 5.00 (10-6) cm2sec-1 at 25oC which agreed with Gosting diffusion measurement - using the MW you can calculate S - they also report Gosting values for sucrose (vbar = 0.618 ml/gm).<BR><BR>>>> "John Philo" <jphilo@mailway.com> 11/14/05 11:01 AM >>><BR>
<DIV style="COLOR: #000000">David,<BR><BR>Yes but in order to use this you must know the sedimentation coefficient of<BR>the small molecule and have all the necessary density and viscosity data. <BR><BR>In that regard, does anyone actually have a good sedimentation coefficient<BR>for sucrose, trehalose, and/or mannitol? <BR><BR>John<BR><BR>-----Original Message-----<BR>From: rasmb-bounces@rasmb.bbri.org [<A href="mailto:rasmb-bounces@rasmb.bbri.org]">mailto:rasmb-bounces@rasmb.bbri.org]</A> On<BR>Behalf Of David Scott<BR>Sent: Monday, November 14, 2005 7:39 AM<BR>To: Matthew.Parker@immunogen.com; rasmb@rasmb-email.bbri.org<BR>Subject: Re: [RASMB] High sucrose concentrations in sed velocityexperiments<BR><BR><BR>Hello Matt,<BR><BR>Basically, small solutes will form a dynamic density gradient when you<BR>perform sedimentation velocity. If there are enough around, then you have to<BR>correct for it, which appears to be what you have here. We have a similar<BR>problem as we work with extreme halophilic proteins that are happy only in<BR>molar salt concentrations. Luckily Peter Schuck has written a nice routine<BR>in SEDFIT to correct for this (under options, select inhomogenous gradient,<BR>click "no" to compressible solvent and "yes" to dynamic gradient...). It<BR>takes longer for everything to fit, but gets there in the end. <BR><BR>The full and gory details are in a Biophys. Chem. paper:<BR><BR>P. Schuck (2003) A model for sedimentation in inhomogeneous media. I.<BR>Dynamic density gradients from sedimenting co-solutes. Biophysical<BR>Chemistry 108:187-200<BR><BR>and further details of its implementation in SEDFIT are on Peter's website<BR>under:<BR><BR><A href="http://www.analyticalultracentrifugation.com/dynamic_density_gradients.htm">http://www.analyticalultracentrifugation.com/dynamic_density_gradients.htm</A><BR><BR><BR>Have fun!<BR><BR>Dave Scott.<BR><BR><BR><BR><BR><BR>Dr. David J. Scott<BR>Lecturer in Physical Biochemistry<BR>National Centre for Macromolecular Hydrodynamics<BR>School of Biosciences<BR>University of Nottingham<BR>Sutton Bonington<BR>Leicestershire<BR>LE12 5RD<BR>Phone: +44 (0) 115 951 6221<BR>Fax: +44 (0) 115 951 6142<BR>Email: dj.scott@nottingham.ac.uk<BR><A href="http://www.nottingham.ac.uk/biosciences/foodsci/academic/scott.html">http://www.nottingham.ac.uk/biosciences/foodsci/academic/scott.html</A> <BR><BR>>>> "Parker, Matthew" <Matthew.Parker@immunogen.com> 11/14/05 3:24 pm <BR>>>> >>><BR> Hi. We recently ran sedimentation velocity on some samples that<BR>contained 10% sucrose in the buffer. We obtained results for the c(s)<BR>distribution that didn't agree well with what we saw by SEC, and the<BR>s-values were also shifted to significantly lower values than what we would<BR>expect (and that we have seen in other formulations) for an IgG. It was<BR>suggested to us that our sucrose concentration was high enough to create a<BR>sucrose gradient in the cell during the course of the run, and that this<BR>could cause the relative peak areas in the c(s) plot to be inaccurate.<BR><BR><BR><BR> Does anybody have any comments about this, or suggestions about<BR>how high in sucrose content you can go before this starts to become a<BR>problem?<BR><BR><BR><BR> Thanks,<BR><BR><BR><BR> Matt<BR><BR><BR><BR>Matthew Parker, Ph.D.<BR><BR>Analytical and Pharmaceutical Sciences<BR><BR>Immunogen, Inc.<BR><BR>Cambridge, MA<BR><BR><BR><BR>This message has been checked for viruses but the contents of an attachment<BR>may still contain software viruses, which could damage your computer system:<BR>you are advised to perform your own checks. Email communications with the<BR>University of Nottingham may be monitored as permitted by UK legislation.<BR><BR>_______________________________________________<BR>RASMB mailing list<BR>RASMB@rasmb.bbri.org <A href="http://rasmb.bbri.org/mailman/listinfo/rasmb">http://rasmb.bbri.org/mailman/listinfo/rasmb</A><BR><BR><BR><BR>_______________________________________________<BR>RASMB mailing list<BR>RASMB@rasmb.bbri.org<BR><A href="http://rasmb.bbri.org/mailman/listinfo/rasmb">http://rasmb.bbri.org/mailman/listinfo/rasmb</A><BR><BR></DIV></BODY></HTML>