How to set up H1 T2 (or T1rho) expts. using 90%H2O/10%D2O buffer

Generally, T2 (and T1rho) relaxation times of large protein biomolecules are getting significantly shorter after aggregation happening, or ligand binding; so two spectra can be measured e.g. one with 10 ms relaxation delay time and another with like 200 ms, the corresponding peaks should be getting broaden and peaks intensities should be getting weaken.

  1. Don’t spin the sample, run ZGPR first, and calibrate proton 90 pulse p1 by pulsecal; find proper o1 by gs. And it’s good to run ZGESGP too.
  2. Load SCREEN_T2_hw (with the pulse sequence cpmg_esgp2d) parameters folder from …/par/user/ (on B800-Luke), update p1, o1, sw.
  3. Edit vclist, set ncyc like 5 and 98; and then set TD1 as the total number of ncycs in vclist (2 here); use default d1=2s; ns=16 at first.
  4. rga, and zg.


  1. In this sequence, T2 delay time = ncyc*d31 = ncyc*(d20*4 + p2*2);
  2. So ncyc = 5 and 98 in vclist is corresponding to the T2 delay time as: 10.17ms, 199.36ms, (d20=0.5ms, p2=17.14us — 180° H1 pulse length on B800-Luke here).

For T1rho measurements, t1rho_esgp2d sequence will be used, and SCREEN_T1R_hw parameters folder from …/par/user/ (on B800-Luke) will be loaded. Edit vplist, set like 10m and 200m as the delay time for spin lock sequence; and then set TD1 as the total number of delay time points in vplist (2 here); use default d1=2s; ns=16 at first.

Hongwei edited on 2024-03-20