Dear all,
I’ve been tearing my hair out trying to figure out how to choose relaxation
dispersion models for a particular protein. I’ve ran into a case where many
residues are fit to the ‘IT99’ model, but did not fit to the ’NS CPMG 2-site
expanded’ model (relax doesn’t even bother to show the Chi2 and AIC in the
log file). If I understand correctly, the ’NS CPMG 2-site expanded’ model is
an exact numerical solution based on the original Bloch-McConnell equations,
whereas ‘IT99’ is an analytical approximation. I would expect that whatever
can be fit with the ‘IT99’ model should also be able to fit to the ’NS CPMG
2-site expanded’ model since they seem to share the same restrictions (pA >
pB). Or am I missing something?
Cheers,
Chung-ke
Question on choosing relaxation dispersion models for proteins