Hello-- > I am refining a protein structure with PCS as the only experimental > restraint. I am using the python script in which the PCSpot is > modified from RDCpot. What is the unit of force constant for PCS in > python script?
kcal/mol/x^2, where x is the units of your observed PCS values. This will also be the units for the Da of the alignment tensor, which you can set explicitly or fit using calcTensor, or calcXTensor. > And which values are appropriate? This really depends on the magnitude of your pcs values. I have seen some very large force constants, so you might start with a value of, say, 100, and see how nonbonded, bond, angle, etc violations are, and see how the fit to experiment is. Increase or decrease by factors of 10 until you get a better feel. I hope this helps-- Charles _______________________________________________ Xplor-nih mailing list [email protected] https://dcb.cit.nih.gov/mailman/listinfo/xplor-nih
