From: Geoff=Howlett%BioChem%UNIMELB@muwaye.unimelb.EDU.AU
  To  : rasmb@bbri.eri.harvard.edu
  Date: Sun, 1 May 94 8:26:35 +1000

...no subject...

Re. High temperature runs:

The presentations Ernesto Freire made when he was here impressed me with the 
need to identify the driving forces in protein folding.

To the extent that the folding problem is considered the "second part of the 
genetic code" there should be a growing demand for free energy and enthalpy 
changes to be determined over a range of temperature.  Perhaps if Ernesto is 
monitoring these conversations he could comment.

Recent experiments with Ernesto have been aimed at rationalising 
microcalorimetry data (obtained over a temperature range 20-90 degrees) which 
suggest peptide dimerisation and ultracentrifugation data (at 20-40 degrees) 
which favour a monomeric model.  The ability to look at the system in the 
centrifuge at high temperatures would be very useful. Recall that the 
centrifuge is uniquely placed to distinguish monomer-dimer-trimer-tetramer 
models which form the basis for the interpretation of microcalorimetry and 
spectroscopic data.

How difficult would it be to modify the XLA for high temperature runs?  How 
expensive?   What is the experience with the current XLA at temperatures 
higher than 40 degrees?

Geoff H.