Batch process DS Solvent Accessibility calculation for all pdb files in a directory.

This script (for use with DS 2.1) calculates the changes of residue SAS values upon formation of protein AB complex:

Delta {SAS} = {SAS}of A alone + {SAS}of B alone - {SAS}of AB complex

SAS data are saved in a CSV (comma separated value) file for each of the pdb file processed.

Each output CSV file will include 3 sets of data:
(1) The per residue data for Residue SAS, Percent SAS, and Side-Chain SAS, for the protein AB complex.
(2) The per residue data for Residue SAS, Percent SAS, and Side-Chain SAS, for A alone and B alone.
(3) The per residue data of the difference between (2) and (1).

The total change of Residue SAS, Side-Chain SAS for the protein complex formation are also reported at the last row of the CSV file.