IT99

The Ishima and Torchia 1999 2-site exchange on all times scales with the constraint that $p_A \gg p_B$ for SQ CPMG-type data. This model is labelled as IT99 in relax.

Parameters

The IT99 model has the parameters {$R_2^0$, $...$, $p_A$, $\Delta\omega$, $\tau_\textrm{ex}$}.

Reference

The reference for the IT99 model is:

• Ishima, R. and Torchia, D. (1999). Estimating the time scale of chemical exchange of proteins from measurements of transverse relaxation rates in solution. J. Biomol. NMR, 14(4), 369-372. (10.1023/A:1008324025406).

Links

The implementation of the IT99 model in relax can be seen in the:

• relax manual,
• API documentation,
• relaxation dispersion page of the relax website.