Mutates every single protein residue to Ala without moving the neighbours and produces a file with the resulting free Gibbs energies of alanine mutation. It is usefull for a fast scan, given that polar interactions and clashes in a residue are both disrupted while mutating to alanine. The minimal configuration file for AlaScan is:


It can be run using the command line:

FoldX --command=AlaScan --pdb=AS.pdb

FoldX uses output-file as a tag to label different outputs from different commands in batch runs. After running AlaScan you'll get one file to look at. Given output-file="TAG" the output file is:

  • TAG_AS.fxout Contains DDGs of mutating to alanine all residues in the pdb.

If you don't set output-file, TAG will be the pdbId of the first pdb on the batch. The output file looks like this:

ASP 1 to ALA energy change is 0.0840787
VAL 213 to ALA energy change is -0.443878

The value is the DDG upon alanine mutation in Kcal/mol.