As described in the paper:
Protein structural ensembles visualized by solvent paramagnetic relaxation enhancement
What is sPRE-calc
sPRE-calc is a fortran program to calculate the theoretical value of solvent PRE using grid model approach. The solvent effect for a proton is integrated over all the grid points, as defined in the following equation.
Here, the ωl,m,n has a value of 1 if the paramagnetic probe is allowed for grid point (l, m, n), and 0 for excluded points taken up by the molecule.
How to use sPRE-calc
Install : tar xjvf sPRE.tar.bz2; chmod a+x sPRE.x
Usage : ./sPRE.x (pdb file) (Rprobe) (Dpara) (Atom)
Rprobe: the size of paramagnetic probe
Dpara : the concentricity of paramagnetic center, 0 means right at the center
Atom : the name of atom used for sPRE calculation, which will list in the third column of the output. 'HM' represents protons of methyl group
Example of output file