From: Joel Mackay <j.mackay@biochem.usyd.edu.au>
  To  : rasmb@bbri.org
  Date: Tue, 29 Jun 1999 14:13:43 +1000

more vbar...

Dear all,
I have been asked to run some equilibrium experiments on a (water-soluble)
inorganic macrocycle (monomer MW ~ 9 kDa). Are there any ways to calculate
values for vbar for non-protein molecules? It seems, from the discussions
of the last week or so, that measuring vbar experimentally is not a simple
exercise, and that it requires quite a bit of material and patience, not to
mention a densitometer (which we don't have).
A related quiestion: Is it reasonable to calculate vbar from known crystal
(or NMR) structures by simply measuring the volume of the molecule and
dividing by the molecular mass, or have I missed something?
thanks for your help,
Joel Mackay
************************************************************************
Dr Joel Mackay			ph +61-2-9351-3906
ARC Research Fellow			fax +61-2-9351-4726
Department of Biochemistry
University of Sydney
NSW 2006 Australia
http://www.biochem.usyd.edu.au/~joel/
************************************************************************

Date: Tue, 22 Jun 1999 09:48:21 -0500
From: "Jonathan M. Sparks" <Sparks@tamu.edu>
Reply-To: sparks@tamu.edu
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To: rasmb@bbri.harvard.edu
Subject: Helical peptides
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I was wondering if anyone could shed some light on  a problem that i am
having.

In collaboration with another lab here at Texas A&M we are trying to
determine if some large (100-300 residue) synthetic helical peptides
oligomerize.

Fitting the results of an equillibrium run to a single sed. model, the
resulting molecular mass is less than that of the monomer.  Has anyone
tried similar experiments and determined molecular weights that are well
below reasonable?  Although shape shouldn't alter the results of an
equillibrium run, does the fact that they are such long helixes
influence their distribution?

Any help would be appreciated!
Thanks.
Jon

--
*******************
Jonathan M. Sparks
Department of Biochemistry
Texas A&M University
College Station, TX 77843

(409) 775-6465  (H)
(409) 845-8971  (Lab)
Sparks@tamu.edu
*******************



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