Hi, The 10 seconds for the NOE seems a little excessive (unless this is an IDP or very small protein). Have you quantified the time required for recovery? As for the peak picking and fitting, my experience is that with the proper temperature control and calibration, then the following routine is the most accurate for extracting relaxation rates (this is yet to be published):
- Shift all peaks to their maximum in each spectrum (pc in Sparky for example). - Average the peak lists across all spectra for one relaxation data set. - Measure peak heights using the averaged peak lists. I would not touch volume integration. One other thing you need to be very careful with is sample concentration. If you require multiple samples then you should aim to have identical protein concentrations (volume does not matter). Slight concentration differences can have a large effect on the global tumbling of you system, hence the data cannot be combined. I hope some of this helps. Regards, Edward On 5 February 2013 09:52, Martin Ballaschk <[email protected]> wrote: > Hi Edward, > > a part of my mail is missing, it seems like I accidentally sent a draft > version. > > Although it's maybe not that important, here is the rest of the final > paragraph: > > „I don't know if inaccurate or inconsistent data would favor such a behavior. > We now use selective proton pulses in the R1 and NOE-experiments (like > described in [1]), temperature compensation for our R1 pulse programs, > single-scan interleaving for all experiments, accurate temperature > calibration with d4-methanol and automated and hence reproducable peak > picking and fitting routines, and recycle delays of 10s in the HetNOE. The > consistency of the data from two fields was well below 8% even when the > temperature was (accidentally) off by 1K.“ > > Regards, > Martin > > > [1] Lakomek N-A, Ying J, Bax A (2012) Measurement of 15N relaxation rates in > perdeuterated proteins by TROSY-based methods. J Biomol NMR 53: 209–221. > doi:10.1007/s10858-012-9626-5. > -- > Martin Ballaschk > AG Schmieder > Leibniz-Institut für Molekulare Pharmakologie > Robert-Rössle-Str. 10 > 13125 Berlin > [email protected] > Tel.: +49-30-94793-234/315 > Büro: A 1.26 > Labor: C 1.10 > > > _______________________________________________ > relax (http://www.nmr-relax.com) > > This is the relax-users mailing list > [email protected] > > To unsubscribe from this list, get a password > reminder, or change your subscription options, > visit the list information page at > https://mail.gna.org/listinfo/relax-users _______________________________________________ relax (http://www.nmr-relax.com) This is the relax-users mailing list [email protected] To unsubscribe from this list, get a password reminder, or change your subscription options, visit the list information page at https://mail.gna.org/listinfo/relax-users
