Dear NMR managers and others out there,
I am trying to set up and run a straight saturation transfer experiment
and Saturation Transfer Difference experiment on a small protein
fragment that is undergoing a slow two site exchange folding and
unfolding process in D2O. The lifetimes of the states are about twenty
seconds in each state according to other techniques and the population
partitions can be smoothly controlled over a range of 0 to 50 with about
a 50/50 partition at 25 degrees C. The T1 relaxation times of the non
exchangeable aromatic resonances being used to probe the exchange are
about 2.4 seconds. Using the protocols that I think should work I see no
saturation transfer regardless of the length of the saturation times and
powers that I use.
Can anyone point me in a good direction with suggestions of what pulse
sequence and relevant parameters I should use to capture the exchange
rates? I am running the experiments on Varian Inova 600 MHz or 500 MHz
NMR spectrometers. Thank you.
--
Francis Picart
NMR Coordinator
Department of Chemistry
State University of New York at Stony Brook
Room 507
Stony Brook, New York 11794-3400
(631)632-7991
Received on Wed Mar 23 2005 - 17:01:24 MST