vmd.atomsel.sasa

atomsel.sasa()

Get solvent accessible surface area of selection

Parameters:

• srad (float) – Solvent radius
• samples (int) – Maximum number of sample points per atom. Defaults to 500
• points (bool) – True to also return the coordinates of surface points. Defaults to True.
• restrict (atomsel) – Calculate SASA contributions from atoms in this selection only. Useful for getting SASA of residues in the context of their environment. Optional

Returns:

(float) – Solvent accessible surface area OR (float, list of 3-tuple): SASA, points, if points=True

Example to get percent solvent accssibility of a ligand

>>> big_sel = atomsel('protein or resname LIG')
>>> lig_sel = atomsel('resname LIG')
>>> ligand_in_protein_sasa = big_sel.sasa(srad=1.4, restrict=lig_sel)
>>> ligand_alone_sasa, points = lig_sel.sasa(srad=1.4, points=True)
>>> print(100. * ligand_in_protein_sasa / ligand_alone_sasa)