Hi Edward,
Yes - what we did was made sure all the R2 experiments were mixed up so
that you wouldn't have any problem with sample heating (so 10 ms followed
by 1000 ms etc.). We also did two datasets for each of T1 and T2
experiment, alternating T1 and T2 datasets in order to compensate for
sample heating. Temperature didn't go up or anything. I don't know about
the calibration, I think we did this on the first protein we did and it
was fine... Would you recommend using the methanol then, would you say you
see much of a difference?
I did do the consistency testing, wasn't really sure which results to
throw away, do you have a margin within which you would expect most
experiments? I just left out those results which were really off.
I did just redo the peak picking for this protein and actually the
results are coming out fine now, it didn't like just having the same point
picked in each spectrum, it needed the actual peaks picked, no matter how
small. Also I've just noticed in the manual it says to do the RMSD of an
area which doesn't have peaks in - I didn't realise this, I thought it was
over the whole spectrum, so I've changed that now too - although I imagine
it won't have an effect on the actual results, just their errors?
Maddy
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Hi Maddy,
It could well be that there is an issue with the data. I was
wondering if you'd seen Sebastian Morin's consistency testing work
before? This is part of relax and can be used to check the data. See
http://www.nmr-relax.com/refs.html#Morin09. Considering this is the
R2, there could have been sample heating problems. Are these
experiments temperature compensated? And did you calibrate your
temperatures on MeOH using a single scan directly after a partial R2
experiment completed?
Regards,
Edward
Temperature calibration T2