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<TITLE>Re: [RASMB] Urea diffusion and sedimentation coefficient (further)</TITLE>
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<BLOCKQUOTE>Greetings everyone<BR>
<BR>
(and especially those interested in the rather obscure topic of the diffusion coefficient of urea)<BR>
<BR>
Further to my earlier mail (below), two further things to be added:<BR>
<BR>
(1) I am much indebted to Dr Trushar Patel for mailing me a reference to a paper from a more 'classical' age which gives values for the diffusion coefficient of urea (and a range of other solutes) at temperatures from 1º to 37º :<BR>
<BR>
L G Longsworth (1954) "Temperature dependence of diffusion in aqueous solutions" J Phys Chem 58 770-773<BR>
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(2) I have found a very recent publication (June 2007) which explores the issue by molecular dynamics, and comes to the conclusion that at the urea levels commonly used for protein denaturation, urea is about 20% is dimeric:<BR>
<BR>
Stump & Grubmüller (2007) J Phys Chem B 111 6220-6228<BR>
<BR>
Arthur<BR>
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Arthur J Rowe<BR>
Professor of Biomolecular Technology<BR>
NCMH Business Centre<BR>
University of Nottingham<BR>
School of Biosciences<BR>
Sutton Bonington<BR>
Leicestershire LE12 5RD UK<BR>
<BR>
Tel: +44 (0)115 951 6156<BR>
+44 (0)116 271 4502<BR>
Fax: +44 (0)115 951 6157<BR>
email: arthur.rowe@nottingham.ac.uk<BR>
Web: www.nottingham.ac.uk/ncmh/business<BR>
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<BLOCKQUOTE><TT>Hello All<BR>
Does anyone have to hand the diffusion and sedimentation coefficient for<BR>
Urea?<BR>
cheers<BR>
<BR>
dave.<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 Campus<BR>
Sutton Bonington<BR>
Leicestershire<BR>
LE12 5RD<BR>
United Kingdom<BR>
dj.scott@nottingham.ac.uk<BR>
www.nottingham.ac.uk/ncmh<BR>
+44 (0) 115 951 6221 Phone<BR>
+44 (0) 115 951 6142 Fax<BR>
<BR>
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