cljff.add(pol_tip4p, MGIdx(0))
cljff.add(waters, MGIdx(1))
system = System()
system.add(cljff)
print(system.energies())
polchgs = PolariseCharges(cljff[MGIdx(0)], cljff.components().coulomb(),
CoulombProbe(1*mod_electron))
system.add(polchgs)
system.add(polchgs.selfEnergyFF())
print("Applying the polarisation constraint...")
system.applyConstraints()
print(system.energies())
pol_tip4p = system[MGIdx(0)][pol_tip4p.number()].molecule()
print("MM charges\n",tip4p.property("charge"), \
tip4p.evaluate().charge({"charge":"charge"}))
print("Fixed charges\n",pol_tip4p.property("fixed_charge"), \
pol_tip4p.evaluate().charge({"charge":"fixed_charge"}))
print("Induced charges\n",pol_tip4p.property("induced_charge"), \
pol_tip4p.evaluate().charge({"charge":"induced_charge"}))
print("New charges\n",pol_tip4p.property("charge"), \
pol_tip4p.evaluate().charge({"charge":"charge"}))
grid = RegularGrid(tip4p.evaluate().center(), 10, 1.0*angstrom)
def loadQMMMSystem():
"""This function is called to set up the system. It sets everything
up, then returns a System object that holds the configured system"""
print("Loading the system...")
t = QTime()
if os.path.exists(s3file.val):
print("Loading existing s3 file %s..." % s3file.val)
loadsys = Sire.Stream.load(s3file.val)
else:
print("Loading from Amber files %s / %s..." %
(topfile.val, crdfile.val))
# Add the name of the ligand to the list of solute molecules
sys_scheme = NamingScheme()
sys_scheme.addSoluteResidueName(ligand_name.val)
# Load up the system. This will automatically find the protein, solute, water, solvent
# and ion molecules and assign them to different groups
loadsys = createSystem(topfile.val, crdfile.val, sys_scheme)
ligand_mol = findMolecule(loadsys, ligand_name.val)
if ligand_mol is None:
print(
"Cannot find the ligand (%s) in the set of loaded molecules!" %
ligand_name.val)
sys.exit(-1)
# Center the system with the ligand at (0,0,0)
loadsys = centerSystem(loadsys, ligand_mol)
ligand_mol = loadsys[ligand_mol.number()][0].molecule()
if reflection_radius.val is None:
loadsys = addFlexibility(loadsys, naming_scheme=sys_scheme)
else:
loadsys = addFlexibility(loadsys,
Vector(0),
reflection_radius.val,
naming_scheme=sys_scheme)
Sire.Stream.save(loadsys, s3file.val)
ligand_mol = findMolecule(loadsys, ligand_name.val)
if ligand_mol is None:
print("Cannot find the ligand (%s) in the set of loaded molecules!" %
ligand_name.val)
sys.exit(-1)
# Now build the QM/MM system
system = System("QMMM system")
if loadsys.containsProperty("reflection center"):
reflect_center = loadsys.property("reflection center").toVector()[0]
reflect_radius = float(
str(loadsys.property("reflection sphere radius")))
system.setProperty("reflection center",
AtomCoords(CoordGroup(1, reflect_center)))
system.setProperty("reflection sphere radius",
VariantProperty(reflect_radius))
space = Cartesian()
else:
space = loadsys.property("space")
if loadsys.containsProperty("average solute translation delta"):
system.setProperty("average solute translation delta", \
loadsys.property("average solute translation delta"))
if loadsys.containsProperty("average solute rotation delta"):
system.setProperty("average solute rotation delta", \
loadsys.property("average solute rotation delta"))
# create a molecule group to hold all molecules
all_group = MoleculeGroup("all")
# create a molecule group for the ligand
ligand_group = MoleculeGroup("ligand")
ligand_group.add(ligand_mol)
all_group.add(ligand_mol)
groups = []
groups.append(ligand_group)
# pull out the groups that we want from the two systems
# create a group to hold all of the fixed molecules in the bound leg
fixed_group = MoleculeGroup("fixed_molecules")
if MGName("fixed_molecules") in loadsys.mgNames():
fixed_group.add(loadsys[MGName("fixed_molecules")])
if save_pdb.val:
# write a PDB of the fixed atoms in the bound and free legs
if not os.path.exists(outdir.val):
os.makedirs(outdir.val)
PDB().write(fixed_group, "%s/fixed.pdb" % outdir.val)
# create a group to hold all of the mobile solute molecules
mobile_solutes_group = MoleculeGroup("mobile_solutes")
if MGName("mobile_solutes") in loadsys.mgNames():
mobile_solutes_group.add(loadsys[MGName("mobile_solutes")])
mobile_solutes_group.remove(ligand_mol)
if mobile_solutes_group.nMolecules() > 0:
all_group.add(mobile_solutes_group)
groups.append(mobile_solutes_group)
# create a group to hold all of the mobile solvent molecules
mobile_solvents_group = MoleculeGroup("mobile_solvents")
if MGName("mobile_solvents") in loadsys.mgNames():
mols = loadsys[MGName("mobile_solvents")]
for molnum in mols.molNums():
solvent_mol = mols[molnum][0].molecule()
mobile_solvents_group.add(solvent_mol)
all_group.add(mobile_solvents_group)
print("The number of mobile solvent molecules is %d." %
mobile_solvents_group.nMolecules())
groups.append(mobile_solvents_group)
# create the groups to hold all of the protein molecules. We will use "extract" to
# pull out only those protein atoms that are in the mobile region
protein_intra_group = MoleculeGroup("protein_intra_group")
mobile_proteins_group = MoleculeGroup("proteins")
mobile_protein_sidechains_group = MoleculeGroup("mobile_sidechains")
mobile_protein_backbones_group = MoleculeGroup("mobile_backbones")
if MGName("protein_sidechains") in loadsys.mgNames() or \
MGName("protein_backbones") in loadsys.mgNames():
all_proteins = Molecules()
try:
protein_sidechains = loadsys[MGName("protein_sidechains")]
all_proteins.add(protein_sidechains.molecules())
except:
protein_sidechains = MoleculeGroup()
try:
protein_backbones = loadsys[MGName("protein_backbones")]
all_proteins.add(protein_backbones.molecules())
except:
protein_backbones = MoleculeGroup()
try:
boundary_molecules = loadsys[MGName("boundary_molecules")]
all_proteins.add(boundary_molecules.molecules())
except:
boundary_molecules = MoleculeGroup()
for molnum in all_proteins.molNums():
protein_mol = Molecule.join(all_proteins[molnum])
if protein_mol.selectedAll():
protein_intra_group.add(protein_mol)
all_group.add(protein_mol)
mobile_protein = []
if protein_sidechains.contains(molnum):
sidechains = protein_sidechains[molnum]
for sidechain in sidechains:
mobile_protein_sidechains_group.add(sidechain)
mobile_protein += sidechains
if protein_backbones.contains(molnum):
backbones = protein_backbones[molnum]
for backbone in backbones:
mobile_protein_backbones_group.add(backbone)
mobile_protein += backbones
if len(mobile_protein) > 0:
mobile_proteins_group.add(Molecule.join(mobile_protein))
else:
# only some of the atoms have been selected. We will extract
# the mobile atoms and will then update all of the other selections
print("Extracting the mobile atoms of protein %s" %
protein_mol.molecule())
new_protein_mol = protein_mol.extract()
print("Extracted %d mobile atoms from %d total atoms..." % \
(new_protein_mol.nAtoms(), protein_mol.molecule().nAtoms()))
protein_intra_group.add(new_protein_mol)
all_group.add(new_protein_mol)
mobile_protein_view = new_protein_mol.selection()
mobile_protein_view = mobile_protein_view.selectNone()
if protein_sidechains.contains(molnum):
sidechains = protein_sidechains[molnum]
for sidechain in sidechains:
view = new_protein_mol.selection()
view = view.selectNone()
for atomid in sidechain.selection().selectedAtoms():
atom = protein_mol.atom(atomid)
resatomid = ResAtomID(atom.residue().number(),
atom.name())
view = view.select(resatomid)
mobile_protein_view = mobile_protein_view.select(
resatomid)
if view.nSelected() > 0:
mobile_protein_sidechains_group.add(
PartialMolecule(new_protein_mol, view))
if protein_backbones.contains(molnum):
backbones = protein_backbones[molnum]
for backbone in backbones:
view = new_protein_mol.selection()
view = view.selectNone()
for atomid in backbone.selection().selectedAtoms():
atom = protein_mol.atom(atomid)
resatomid = ResAtomID(atom.residue().number(),
atom.name())
view = view.select(resatomid)
mobile_protein_view = mobile_protein_view.select(
resatomid)
if view.nSelected() > 0:
mobile_protein_backbones_group.add(
PartialMolecule(new_protein_mol, view))
print("Number of moved protein sidechain residues = %s" %
mobile_protein_sidechains_group.nViews())
print("Number of moved protein backbone residues = %s" %
mobile_protein_backbones_group.nViews())
if mobile_protein_view.nSelected() > 0:
mobile_proteins_group.add(
PartialMolecule(new_protein_mol, mobile_protein_view))
groups.append(mobile_protein_backbones_group)
groups.append(mobile_protein_sidechains_group)
groups.append(all_group)
# finished added in all of the proteins
for group in groups:
if group.nMolecules() > 0:
print("Adding group %s" % group.name())
system.add(group)
# now add in the forcefields for the system...
print("Creating the forcefields for the QM/MM system...")
# first, group together the molecules grouped above into convenient
# groups for the forcefields
# group holding just the ligand
ligand_mols = ligand_group.molecules()
# group holding all of the mobile atoms
mobile_mols = mobile_solvents_group.molecules()
mobile_mols.add(mobile_solutes_group.molecules())
mobile_mols.add(protein_intra_group.molecules())
# group holding all of the mobile atoms in the bound leg, excluding the
# buffer atoms that are fixed, but bonded to mobile atoms
mobile_buffered_mols = mobile_solvents_group.molecules()
mobile_buffered_mols.add(mobile_solutes_group.molecules())
mobile_buffered_mols.add(mobile_proteins_group.molecules())
# group holding all of the protein molecules that need intramolecular terms calculated
protein_intra_mols = protein_intra_group.molecules()
# group holding all of the solute molecules that nede intramolecular terms calculated
solute_intra_mols = mobile_solutes_group.molecules()
forcefields = []
###
### INTRA-ENERGY OF THE LIGAND AND CLUSTER
###
# intramolecular energy of the ligand
ligand_intraclj = IntraCLJFF("ligand:intraclj")
ligand_intraclj = setCLJProperties(ligand_intraclj, space)
ligand_intraclj.add(ligand_mols)
ligand_intraff = InternalFF("ligand:intra")
ligand_intraff.add(ligand_mols)
forcefields.append(ligand_intraclj)
forcefields.append(ligand_intraff)
ligand_mm_nrg = ligand_intraclj.components().total(
) + ligand_intraff.components().total()
###
### FORCEFIELDS INVOLVING THE LIGAND/CLUSTER AND OTHER ATOMS
###
# forcefield holding the energy between the ligand and the mobile atoms in the
# bound leg
ligand_mobile = InterGroupCLJFF("system:ligand-mobile")
ligand_mobile = setCLJProperties(ligand_mobile, space)
ligand_mobile.add(ligand_mols, MGIdx(0))
ligand_mobile.add(mobile_mols, MGIdx(1))
qm_ligand = QMMMFF("system:ligand-QM")
qm_ligand.add(ligand_mols, MGIdx(0))
qm_ligand = setQMProperties(qm_ligand, space)
zero_energy = 0
if not intermolecular_only.val:
if qm_zero_energy.val is None:
# calculate the delta value for the system - this is the difference between
# the MM and QM intramolecular energy of the ligand
t.start()
print("\nComparing the MM and QM energies of the ligand...")
mm_intra = ligand_intraclj.energy().value(
) + ligand_intraff.energy().value()
print("MM energy = %s kcal mol-1 (took %s ms)" %
(mm_intra, t.elapsed()))
t.start()
zero_sys = System()
zero_sys.add(qm_ligand)
qm_intra = zero_sys.energy().value()
print("QM energy = %s kcal mol-1 (took %s ms)" %
(qm_intra, t.elapsed()))
print("\nSetting the QM zero energy to %s kcal mol-1" %
(qm_intra - mm_intra))
qm_ligand.setZeroEnergy((qm_intra - mm_intra) * kcal_per_mol)
zero_energy = qm_intra - mm_intra
else:
print("\nManually setting the QM zero energy to %s" %
qm_zero_energy.val)
qm_ligand.setZeroEnergy(qm_zero_energy.val)
zero_energy = qm_zero_energy.val
qm_ligand.add(mobile_mols, MGIdx(1))
ligand_mm_nrg += ligand_mobile.components().total()
ligand_qm_nrg = qm_ligand.components().total() + ligand_mobile.components(
).lj()
if intermolecular_only.val:
# the QM model still uses the MM intramolecular energy of the ligand
ligand_qm_nrg += ligand_intraclj.components().total(
) + ligand_intraff.components().total()
forcefields.append(ligand_mobile)
forcefields.append(qm_ligand)
if fixed_group.nMolecules() > 0:
# there are fixed molecules
# Whether or not to disable the grid and calculate all energies atomisticly
if disable_grid:
# we need to renumber all of the fixed molecules so that they don't clash
# with the mobile molecules
print("Renumbering fixed molecules...")
fixed_group = renumberMolecules(fixed_group)
# forcefield holding the energy between the ligand and the fixed atoms in the bound leg
if disable_grid:
ligand_fixed = InterGroupCLJFF("system:ligand-fixed")
ligand_fixed = setCLJProperties(ligand_fixed, space)
ligand_fixed = setFakeGridProperties(ligand_fixed, space)
ligand_fixed.add(ligand_mols, MGIdx(0))
ligand_fixed.add(fixed_group, MGIdx(1))
qm_ligand.add(fixed_group, MGIdx(1))
ligand_mm_nrg += ligand_fixed.components().total()
ligand_qm_nrg += ligand_fixed.components().lj()
forcefields.append(ligand_fixed)
else:
ligand_fixed = GridFF2("system:ligand-fixed")
ligand_fixed = setCLJProperties(ligand_fixed, space)
ligand_fixed = setGridProperties(ligand_fixed)
ligand_fixed.add(ligand_mols, MGIdx(0))
ligand_fixed.addFixedAtoms(fixed_group)
qm_ligand.addFixedAtoms(fixed_group)
ligand_mm_nrg += ligand_fixed.components().total()
ligand_qm_nrg += ligand_fixed.components().lj()
forcefields.append(ligand_fixed)
###
### FORCEFIELDS NOT INVOLVING THE LIGAND
###
# forcefield holding the intermolecular energy between all molecules
mobile_mobile = InterCLJFF("mobile-mobile")
mobile_mobile = setCLJProperties(mobile_mobile, space)
mobile_mobile.add(mobile_mols)
other_nrg = mobile_mobile.components().total()
forcefields.append(mobile_mobile)
# forcefield holding the energy between the mobile atoms and
# the fixed atoms
if disable_grid.val:
mobile_fixed = InterGroupCLJFF("mobile-fixed")
mobile_fixed = setCLJProperties(mobile_fixed)
mobile_fixed = setFakeGridProperties(mobile_fixed, space)
mobile_fixed.add(mobile_buffered_mols, MGIdx(0))
mobile_fixed.add(fixed_group, MGIdx(1))
other_nrg += mobile_fixed.components().total()
forcefields.append(mobile_fixed)
else:
mobile_fixed = GridFF2("mobile-fixed")
mobile_fixed = setCLJProperties(mobile_fixed, space)
mobile_fixed = setGridProperties(mobile_fixed)
# we use mobile_buffered_group as this group misses out atoms that are bonded
# to fixed atoms (thus preventing large energies caused by incorrect non-bonded calculations)
mobile_fixed.add(mobile_buffered_mols, MGIdx(0))
mobile_fixed.addFixedAtoms(fixed_group)
other_nrg += mobile_fixed.components().total()
forcefields.append(mobile_fixed)
# intramolecular energy of the protein
if protein_intra_mols.nMolecules() > 0:
protein_intraclj = IntraCLJFF("protein_intraclj")
protein_intraclj = setCLJProperties(protein_intraclj, space)
protein_intraff = InternalFF("protein_intra")
for molnum in protein_intra_mols.molNums():
protein_mol = Molecule.join(protein_intra_mols[molnum])
protein_intraclj.add(protein_mol)
protein_intraff.add(protein_mol)
other_nrg += protein_intraclj.components().total()
other_nrg += protein_intraff.components().total()
forcefields.append(protein_intraclj)
forcefields.append(protein_intraff)
# intramolecular energy of any other solutes
if solute_intra_mols.nMolecules() > 0:
solute_intraclj = IntraCLJFF("solute_intraclj")
solute_intraclj = setCLJProperties(solute_intraclj, space)
solute_intraff = InternalFF("solute_intra")
for molnum in solute_intra_mols.molNums():
solute_mol = Molecule.join(solute_intra_mols[molnum])
solute_intraclj.add(solute_mol)
solute_intraff.add(solute_mol)
other_nrg += solute_intraclj.components().total()
other_nrg += solute_intraff.components().total()
forcefields.append(solute_intraclj)
forcefields.append(solute_intraff)
###
### NOW ADD THE FORCEFIELDS TO THE SYSTEM
###
###
### SETTING THE FORCEFIELD EXPRESSIONS
###
lam = Symbol("lambda")
e_slow = ((1 - lam) * ligand_qm_nrg) + (lam * ligand_mm_nrg) + other_nrg
e_fast = ligand_mm_nrg + other_nrg
de_by_dlam = ligand_mm_nrg - ligand_qm_nrg
for forcefield in forcefields:
system.add(forcefield)
system.setConstant(lam, 0.0)
system.setComponent(Symbol("E_{fast}"), e_fast)
system.setComponent(Symbol("E_{slow}"), e_slow)
system.setComponent(Symbol("dE/dlam"), de_by_dlam)
system.setComponent(system.totalComponent(), e_slow)
system.setProperty("space", space)
if space.isPeriodic():
# ensure that all molecules are wrapped into the space with the ligand at the center
print("Adding in a space wrapper constraint %s, %s" %
(space, ligand_mol.evaluate().center()))
system.add(SpaceWrapper(ligand_mol.evaluate().center(), all_group))
system.applyConstraints()
print("\nHere are the values of all of the initial energy components...")
t.start()
printEnergies(system.energies())
print("(these took %d ms to evaluate)\n" % t.elapsed())
# Create a monitor to monitor the free energy average
system.add("dG/dlam",
MonitorComponent(Symbol("dE/dlam"), AverageAndStddev()))
if intermolecular_only.val:
print(
"\n\n## This simulation uses QM to model *only* the intermolecular energy between"
)
print(
"## the QM and MM atoms. The intramolecular energy of the QM atoms is still"
)
print("## modelled using MM.\n")
else:
print(
"\n\n## This simulation uses QM to model both the intermolecular and intramolecular"
)
print(
"## energies of the QM atoms. Because the this, we have to adjust the 'zero' point"
)
print(
"## of the QM potential. You need to add the value %s kcal mol-1 back onto the"
% zero_energy)
print("## QM->MM free energy calculated using this program.\n")
return system
def createSystemFrom(molecules, space, system_name, naming_scheme = NamingScheme()):
"""Create a new System from the passed molecules and space,
sorting the molecules into different molecule groups based on the
passed naming scheme"""
system = System(system_name)
# If requested, change the water model for all water molecules
if water_model.val == "tip4p":
molnums = molecules.molNums()
new_molecules = Molecules()
print("Forcing all water molecules to use the %s water model..." % water_model.val)
print("Converting %d molecules..." % len(molnums))
i = 0
for molnum in molnums:
molecule = molecules[molnum].molecule()
if i % 100 == 0:
print("%d" % i)
sys.stdout.flush()
elif i % 10 == 0:
print(".", end=' ')
sys.stdout.flush()
i += 1
if molecule.nAtoms() == 3:
# this could be a TIP3P water
resname =str(molecule.residue().name().value()).lower()
if resname == "wat" or resname == "t3p":
new_molecule = convertTip3PtoTip4P(molecule)
if new_molecule:
molecule = new_molecule
new_molecules.add(molecule)
print("%d" % i)
molecules = new_molecules
nmols = molecules.nMolecules()
print("Number of molecules == %s" % nmols)
print("System space == %s" % space)
if nmols == 0:
return system
print("Assigning molecules to molecule groups...")
solute_group = MoleculeGroup(naming_scheme.solutesGroupName().value())
protein_group = MoleculeGroup(naming_scheme.proteinsGroupName().value())
solvent_group = MoleculeGroup(naming_scheme.solventsGroupName().value())
water_group = MoleculeGroup(naming_scheme.watersGroupName().value())
ion_group = MoleculeGroup(naming_scheme.ionsGroupName().value())
all_group = MoleculeGroup(naming_scheme.allMoleculesGroupName().value())
# The all molecules group has all of the molecules
all_group.add(molecules)
system.add(all_group)
# Run through each molecule and decide what type it is...
molnums = molecules.molNums()
molnums.sort()
central_molecule = None
solutes = []
proteins = []
solvents = []
waters = []
ions = []
for molnum in molnums:
molecule = molecules[molnum].molecule()
resnams = getResidueNames(molecule)
if naming_scheme.isSolute(resnams):
solutes.append(molecule)
elif naming_scheme.isProtein(resnams):
proteins.append(molecule)
elif naming_scheme.isWater(resnams):
waters.append(molecule)
elif naming_scheme.isIon(resnams):
ions.append(molecule)
elif molecule.nResidues() == 1:
solvents.append(molecule)
else:
solutes.append(molecule)
# Ok - we have now divided everything up into groups
for solute in solutes:
solute_group.add(solute)
for protein in proteins:
protein_group.add(protein)
for water in waters:
solvent_group.add(water)
water_group.add(water)
for solvent in solvents:
solvent_group.add(solvent)
for ion in ions:
solvent_group.add(ion)
ion_group.add(ion)
if solute_group.nMolecules() > 0:
system.add(solute_group)
if protein_group.nMolecules() > 0:
system.add(protein_group)
if solvent_group.nMolecules() > 0:
system.add(solvent_group)
if water_group.nMolecules() > 0:
system.add(water_group)
if ion_group.nMolecules() > 0:
system.add(ion_group)
print("Number of solute molecules == %s" % solute_group.nMolecules())
print("Number of protein molecules == %s" % protein_group.nMolecules())
print("Number of ions == %s" % ion_group.nMolecules())
print("Number of water molecules == %s" % water_group.nMolecules())
print("Number of solvent molecules == %s" % solvent_group.nMolecules())
print("(solvent group is waters + ions + unidentified single-residue molecules)")
system.setProperty("space", space)
system.add( SpaceWrapper( Vector(0), all_group ) )
system.applyConstraints()
print("Returning the constructed system")
return system
def loadQMMMSystem():
"""This function is called to set up the system. It sets everything
up, then returns a System object that holds the configured system"""
print("Loading the system...")
t = QTime()
if os.path.exists(s3file.val):
print("Loading existing s3 file %s..." % s3file.val)
loadsys = Sire.Stream.load(s3file.val)
else:
print("Loading from Amber files %s / %s..." % (topfile.val, crdfile.val))
# Add the name of the ligand to the list of solute molecules
sys_scheme = NamingScheme()
sys_scheme.addSoluteResidueName(ligand_name.val)
# Load up the system. This will automatically find the protein, solute, water, solvent
# and ion molecules and assign them to different groups
loadsys = createSystem(topfile.val, crdfile.val, sys_scheme)
ligand_mol = findMolecule(loadsys, ligand_name.val)
if ligand_mol is None:
print("Cannot find the ligand (%s) in the set of loaded molecules!" % ligand_name.val)
sys.exit(-1)
# Center the system with the ligand at (0,0,0)
loadsys = centerSystem(loadsys, ligand_mol)
ligand_mol = loadsys[ligand_mol.number()].molecule()
if reflection_radius.val is None:
loadsys = addFlexibility(loadsys, naming_scheme=sys_scheme )
else:
loadsys = addFlexibility(loadsys, Vector(0), reflection_radius.val, naming_scheme=sys_scheme)
Sire.Stream.save(loadsys, s3file.val)
ligand_mol = findMolecule(loadsys, ligand_name.val)
if ligand_mol is None:
print("Cannot find the ligand (%s) in the set of loaded molecules!" % ligand_name.val)
sys.exit(-1)
# Now build the QM/MM system
system = System("QMMM system")
if loadsys.containsProperty("reflection center"):
reflect_center = loadsys.property("reflection center").toVector()[0]
reflect_radius = float(str(loadsys.property("reflection sphere radius")))
system.setProperty("reflection center", AtomCoords(CoordGroup(1,reflect_center)))
system.setProperty("reflection sphere radius", VariantProperty(reflect_radius))
space = Cartesian()
else:
space = loadsys.property("space")
if loadsys.containsProperty("average solute translation delta"):
system.setProperty("average solute translation delta", \
loadsys.property("average solute translation delta"))
if loadsys.containsProperty("average solute rotation delta"):
system.setProperty("average solute rotation delta", \
loadsys.property("average solute rotation delta"))
# create a molecule group to hold all molecules
all_group = MoleculeGroup("all")
# create a molecule group for the ligand
ligand_group = MoleculeGroup("ligand")
ligand_group.add(ligand_mol)
all_group.add(ligand_mol)
groups = []
groups.append(ligand_group)
# pull out the groups that we want from the two systems
# create a group to hold all of the fixed molecules in the bound leg
fixed_group = MoleculeGroup("fixed_molecules")
if MGName("fixed_molecules") in loadsys.mgNames():
fixed_group.add( loadsys[ MGName("fixed_molecules") ] )
if save_pdb.val:
# write a PDB of the fixed atoms in the bound and free legs
if not os.path.exists(outdir.val):
os.makedirs(outdir.val)
PDB().write(fixed_group, "%s/fixed.pdb" % outdir.val)
# create a group to hold all of the mobile solute molecules
mobile_solutes_group = MoleculeGroup("mobile_solutes")
if MGName("mobile_solutes") in loadsys.mgNames():
mobile_solutes_group.add( loadsys[MGName("mobile_solutes")] )
mobile_solutes_group.remove(ligand_mol)
if mobile_solutes_group.nMolecules() > 0:
all_group.add(mobile_solutes_group)
groups.append(mobile_solutes_group)
# create a group to hold all of the mobile solvent molecules
mobile_solvents_group = MoleculeGroup("mobile_solvents")
if MGName("mobile_solvents") in loadsys.mgNames():
mols = loadsys[MGName("mobile_solvents")]
for molnum in mols.molNums():
solvent_mol = mols[molnum].molecule()
mobile_solvents_group.add(solvent_mol)
all_group.add(mobile_solvents_group)
print("The number of mobile solvent molecules is %d." % mobile_solvents_group.nMolecules())
groups.append(mobile_solvents_group)
# create the groups to hold all of the protein molecules. We will use "extract" to
# pull out only those protein atoms that are in the mobile region
protein_intra_group = MoleculeGroup("protein_intra_group")
mobile_proteins_group = MoleculeGroup("proteins")
mobile_protein_sidechains_group = MoleculeGroup("mobile_sidechains")
mobile_protein_backbones_group = MoleculeGroup("mobile_backbones")
if MGName("protein_sidechains") in loadsys.mgNames() or \
MGName("protein_backbones") in loadsys.mgNames():
all_proteins = Molecules()
try:
protein_sidechains = loadsys[MGName("protein_sidechains")]
all_proteins.add(protein_sidechains.molecules())
except:
protein_sidechains = MoleculeGroup()
try:
protein_backbones = loadsys[MGName("protein_backbones")]
all_proteins.add(protein_backbones.molecules())
except:
protein_backbones = MoleculeGroup()
try:
boundary_molecules = loadsys[MGName("boundary_molecules")]
all_proteins.add(boundary_molecules.molecules())
except:
boundary_molecules = MoleculeGroup()
for molnum in all_proteins.molNums():
protein_mol = all_proteins[molnum].join()
if protein_mol.selectedAll():
protein_intra_group.add(protein_mol)
all_group.add(protein_mol)
mobile_protein = None
try:
mobile_protein = protein_sidechains[molnum]
mobile_protein_sidechains_group.add( mobile_protein )
except:
pass
try:
if mobile_protein is None:
mobile_protein = protein_backbones[molnum]
mobile_protein_backbones_group.add( mobile_protein )
else:
mobile_protein.add( protein_backbones[molnum].selection() )
mobile_protein_backbones_group.add( protein_backbones[molnum] )
except:
pass
if not (mobile_protein is None):
mobile_proteins_group.add( mobile_protein.join() )
else:
# only some of the atoms have been selected. We will extract
# the mobile atoms and will then update all of the other selections
print("Extracting the mobile atoms of protein %s" % protein_mol)
new_protein_mol = protein_mol.extract()
print("Extracted %d mobile atoms from %d total atoms..." % \
(new_protein_mol.nAtoms(), protein_mol.molecule().nAtoms()))
protein_intra_group.add(new_protein_mol)
all_group.add( new_protein_mol )
mobile_protein_view = new_protein_mol.selection()
mobile_protein_view = mobile_protein_view.selectNone()
try:
sidechains = protein_sidechains[molnum]
for i in range(0,sidechains.nViews()):
view = new_protein_mol.selection()
view = view.selectNone()
for atomid in sidechains.viewAt(i).selectedAtoms():
atom = protein_mol.atom(atomid)
resatomid = ResAtomID( atom.residue().number(), atom.name() )
view = view.select( resatomid )
mobile_protein_view = mobile_protein_view.select( resatomid )
if view.nSelected() > 0:
mobile_protein_sidechains_group.add( PartialMolecule(new_protein_mol, view) )
except:
pass
try:
backbones = protein_backbones[molnum]
for i in range(0,backbones.nViews()):
view = new_protein_mol.selection()
view = view.selectNone()
for atomid in backbones.viewAt(i).selectedAtoms():
atom = protein_mol.atom(atomid)
resatomid = ResAtomID( atom.residue().number(), atom.name() )
view = view.select( resatomid )
mobile_protein_view = mobile_protein_view.select( resatomid )
if view.nSelected() > 0:
mobile_protein_backbones_group.add( PartialMolecule(new_protein_mol, view) )
except:
pass
if mobile_protein_view.nSelected() > 0:
mobile_proteins_group.add( PartialMolecule(new_protein_mol, mobile_protein_view) )
groups.append(mobile_protein_backbones_group)
groups.append(mobile_protein_sidechains_group)
groups.append(all_group)
# finished added in all of the proteins
for group in groups:
if group.nMolecules() > 0:
print("Adding group %s" % group.name())
system.add(group)
# now add in the forcefields for the system...
print("Creating the forcefields for the QM/MM system...")
# first, group together the molecules grouped above into convenient
# groups for the forcefields
# group holding just the ligand
ligand_mols = ligand_group.molecules()
# group holding all of the mobile atoms
mobile_mols = mobile_solvents_group.molecules()
mobile_mols.add( mobile_solutes_group.molecules() )
mobile_mols.add( protein_intra_group.molecules() )
# group holding all of the mobile atoms in the bound leg, excluding the
# buffer atoms that are fixed, but bonded to mobile atoms
mobile_buffered_mols = mobile_solvents_group.molecules()
mobile_buffered_mols.add( mobile_solutes_group.molecules() )
mobile_buffered_mols.add( mobile_proteins_group.molecules() )
# group holding all of the protein molecules that need intramolecular terms calculated
protein_intra_mols = protein_intra_group.molecules()
# group holding all of the solute molecules that nede intramolecular terms calculated
solute_intra_mols = mobile_solutes_group.molecules()
forcefields = []
###
### INTRA-ENERGY OF THE LIGAND AND CLUSTER
###
# intramolecular energy of the ligand
ligand_intraclj = IntraCLJFF("ligand:intraclj")
ligand_intraclj = setCLJProperties(ligand_intraclj, space)
ligand_intraclj.add(ligand_mols)
ligand_intraff = InternalFF("ligand:intra")
ligand_intraff.add(ligand_mols)
forcefields.append(ligand_intraclj)
forcefields.append(ligand_intraff)
ligand_mm_nrg = ligand_intraclj.components().total() + ligand_intraff.components().total()
###
### FORCEFIELDS INVOLVING THE LIGAND/CLUSTER AND OTHER ATOMS
###
# forcefield holding the energy between the ligand and the mobile atoms in the
# bound leg
ligand_mobile = InterGroupCLJFF("system:ligand-mobile")
ligand_mobile = setCLJProperties(ligand_mobile, space)
ligand_mobile.add(ligand_mols, MGIdx(0))
ligand_mobile.add(mobile_mols, MGIdx(1))
qm_ligand = QMMMFF("system:ligand-QM")
qm_ligand = setQMProperties(qm_ligand, space)
qm_ligand.add(ligand_mols, MGIdx(0))
zero_energy = 0
if not intermolecular_only.val:
if qm_zero_energy.val is None:
# calculate the delta value for the system - this is the difference between
# the MM and QM intramolecular energy of the ligand
t.start()
print("\nComparing the MM and QM energies of the ligand...")
mm_intra = ligand_intraclj.energy().value() + ligand_intraff.energy().value()
print("MM energy = %s kcal mol-1 (took %s ms)" % (mm_intra, t.elapsed()))
t.start()
qm_intra = qm_ligand.energy().value()
print("QM energy = %s kcal mol-1 (took %s ms)" % (qm_intra, t.elapsed()))
print("\nSetting the QM zero energy to %s kcal mol-1" % (qm_intra - mm_intra))
qm_ligand.setZeroEnergy( (qm_intra-mm_intra) * kcal_per_mol )
zero_energy = qm_intra - mm_intra
else:
print("\nManually setting the QM zero energy to %s" % qm_zero_energy.val)
qm_ligand.setZeroEnergy( qm_zero_energy.val )
zero_energy = qm_zero_energy.val
qm_ligand.add(mobile_mols, MGIdx(1))
ligand_mm_nrg += ligand_mobile.components().total()
ligand_qm_nrg = qm_ligand.components().total() + ligand_mobile.components().lj()
if intermolecular_only.val:
# the QM model still uses the MM intramolecular energy of the ligand
ligand_qm_nrg += ligand_intraclj.components().total() + ligand_intraff.components().total()
forcefields.append(ligand_mobile)
forcefields.append(qm_ligand)
if fixed_group.nMolecules() > 0:
# there are fixed molecules
# Whether or not to disable the grid and calculate all energies atomisticly
if disable_grid:
# we need to renumber all of the fixed molecules so that they don't clash
# with the mobile molecules
print("Renumbering fixed molecules...")
fixed_group = renumberMolecules(fixed_group)
# forcefield holding the energy between the ligand and the fixed atoms in the bound leg
if disable_grid:
ligand_fixed = InterGroupCLJFF("system:ligand-fixed")
ligand_fixed = setCLJProperties(ligand_fixed, space)
ligand_fixed = setFakeGridProperties(ligand_fixed, space)
ligand_fixed.add(ligand_mols, MGIdx(0))
ligand_fixed.add(fixed_group, MGIdx(1))
qm_ligand.add(fixed_group, MGIdx(1))
ligand_mm_nrg += ligand_fixed.components().total()
ligand_qm_nrg += ligand_fixed.components().lj()
forcefields.append(ligand_fixed)
else:
ligand_fixed = GridFF("system:ligand-fixed")
ligand_fixed = setCLJProperties(ligand_fixed, space)
ligand_fixed = setGridProperties(ligand_fixed)
ligand_fixed.add(ligand_mols, MGIdx(0))
ligand_fixed.addFixedAtoms( fixed_group )
qm_ligand.addFixedAtoms( fixed_group )
ligand_mm_nrg += ligand_fixed.components().total()
ligand_qm_nrg += ligand_fixed.components().lj()
forcefields.append(ligand_fixed)
###
### FORCEFIELDS NOT INVOLVING THE LIGAND
###
# forcefield holding the intermolecular energy between all molecules
mobile_mobile = InterCLJFF("mobile-mobile")
mobile_mobile = setCLJProperties(mobile_mobile, space)
mobile_mobile.add(mobile_mols)
other_nrg = mobile_mobile.components().total()
forcefields.append(mobile_mobile)
# forcefield holding the energy between the mobile atoms and
# the fixed atoms
if disable_grid.val:
mobile_fixed = InterGroupCLJFF("mobile-fixed")
mobile_fixed = setCLJProperties(mobile_fixed)
mobile_fixed = setFakeGridProperties(mobile_fixed, space)
mobile_fixed.add(mobile_buffered_mols, MGIdx(0))
mobile_fixed.add(fixed_group, MGIdx(1))
other_nrg += mobile_fixed.components().total()
forcefields.append(mobile_fixed)
else:
mobile_fixed = GridFF("mobile-fixed")
mobile_fixed = setCLJProperties(mobile_fixed, space)
mobile_fixed = setGridProperties(mobile_fixed)
# we use mobile_buffered_group as this group misses out atoms that are bonded
# to fixed atoms (thus preventing large energies caused by incorrect non-bonded calculations)
mobile_fixed.add(mobile_buffered_mols, MGIdx(0))
mobile_fixed.addFixedAtoms(fixed_group)
other_nrg += mobile_fixed.components().total()
forcefields.append(mobile_fixed)
# intramolecular energy of the protein
if protein_intra_mols.nMolecules() > 0:
protein_intraclj = IntraCLJFF("protein_intraclj")
protein_intraclj = setCLJProperties(protein_intraclj, space)
protein_intraff = InternalFF("protein_intra")
for molnum in protein_intra_mols.molNums():
protein_mol = protein_intra_mols[molnum].join()
protein_intraclj.add(protein_mol)
protein_intraff.add(protein_mol)
other_nrg += protein_intraclj.components().total()
other_nrg += protein_intraff.components().total()
forcefields.append(protein_intraclj)
forcefields.append(protein_intraff)
# intramolecular energy of any other solutes
if solute_intra_mols.nMolecules() > 0:
solute_intraclj = IntraCLJFF("solute_intraclj")
solute_intraclj = setCLJProperties(solute_intraclj, space)
solute_intraff = InternalFF("solute_intra")
for molnum in solute_intra_mols.molNums():
solute_mol = solute_intra_mols[molnum].join()
solute_intraclj.add(solute_mol)
solute_intraff.add(solute_mol)
other_nrg += solute_intraclj.components().total()
other_nrg += solute_intraff.components().total()
forcefields.append(solute_intraclj)
forcefields.append(solute_intraff)
###
### NOW ADD THE FORCEFIELDS TO THE SYSTEM
###
###
### SETTING THE FORCEFIELD EXPRESSIONS
###
lam = Symbol("lambda")
e_slow = ((1-lam) * ligand_qm_nrg) + (lam * ligand_mm_nrg) + other_nrg
e_fast = ligand_mm_nrg + other_nrg
de_by_dlam = ligand_mm_nrg - ligand_qm_nrg
for forcefield in forcefields:
system.add(forcefield)
system.setConstant(lam, 0.0)
system.setComponent(Symbol("E_{fast}"), e_fast)
system.setComponent(Symbol("E_{slow}"), e_slow)
system.setComponent(Symbol("dE/dlam"), de_by_dlam)
system.setComponent( system.totalComponent(), e_slow )
system.setProperty("space", space)
if space.isPeriodic():
# ensure that all molecules are wrapped into the space with the ligand at the center
print("Adding in a space wrapper constraint %s, %s" % (space, ligand_mol.evaluate().center()))
system.add( SpaceWrapper( ligand_mol.evaluate().center(), all_group ) )
system.applyConstraints()
print("\nHere are the values of all of the initial energy components...")
t.start()
printEnergies(system.energies())
print("(these took %d ms to evaluate)\n" % t.elapsed())
# Create a monitor to monitor the free energy average
system.add( "dG/dlam", MonitorComponent(Symbol("dE/dlam"), AverageAndStddev()) )
if intermolecular_only.val:
print("\n\n## This simulation uses QM to model *only* the intermolecular energy between")
print("## the QM and MM atoms. The intramolecular energy of the QM atoms is still")
print("## modelled using MM.\n")
else:
print("\n\n## This simulation uses QM to model both the intermolecular and intramolecular")
print("## energies of the QM atoms. Because the this, we have to adjust the 'zero' point")
print("## of the QM potential. You need to add the value %s kcal mol-1 back onto the" % zero_energy)
print("## QM->MM free energy calculated using this program.\n")
return system
def createSystemFrom(molecules,
space,
system_name,
naming_scheme=NamingScheme()):
"""Create a new System from the passed molecules and space,
sorting the molecules into different molecule groups based on the
passed naming scheme"""
system = System(system_name)
# If requested, change the water model for all water molecules
if water_model.val == "tip4p":
molnums = molecules.molNums()
new_molecules = Molecules()
print("Forcing all water molecules to use the %s water model..." %
water_model.val)
print("Converting %d molecules..." % len(molnums))
i = 0
for molnum in molnums:
molecule = molecules[molnum].molecule()
if i % 100 == 0:
print("%d" % i)
sys.stdout.flush()
elif i % 10 == 0:
print(".", end=' ')
sys.stdout.flush()
i += 1
if molecule.nAtoms() == 3:
# this could be a TIP3P water
resname = str(molecule.residue().name().value()).lower()
if resname == "wat" or resname == "t3p":
new_molecule = convertTip3PtoTip4P(molecule)
if new_molecule:
molecule = new_molecule
new_molecules.add(molecule)
print("%d" % i)
molecules = new_molecules
nmols = molecules.nMolecules()
print("Number of molecules == %s" % nmols)
print("System space == %s" % space)
if nmols == 0:
return system
print("Assigning molecules to molecule groups...")
solute_group = MoleculeGroup(naming_scheme.solutesGroupName().value())
protein_group = MoleculeGroup(naming_scheme.proteinsGroupName().value())
solvent_group = MoleculeGroup(naming_scheme.solventsGroupName().value())
water_group = MoleculeGroup(naming_scheme.watersGroupName().value())
ion_group = MoleculeGroup(naming_scheme.ionsGroupName().value())
all_group = MoleculeGroup(naming_scheme.allMoleculesGroupName().value())
# The all molecules group has all of the molecules
all_group.add(molecules)
system.add(all_group)
# Run through each molecule and decide what type it is...
molnums = molecules.molNums()
molnums.sort()
central_molecule = None
solutes = []
proteins = []
solvents = []
waters = []
ions = []
for molnum in molnums:
molecule = molecules[molnum].molecule()
resnams = getResidueNames(molecule)
if naming_scheme.isSolute(resnams):
solutes.append(molecule)
elif naming_scheme.isProtein(resnams):
proteins.append(molecule)
elif naming_scheme.isWater(resnams):
waters.append(molecule)
elif naming_scheme.isIon(resnams):
ions.append(molecule)
elif molecule.nResidues() == 1:
solvents.append(molecule)
else:
solutes.append(molecule)
# Ok - we have now divided everything up into groups
for solute in solutes:
solute_group.add(solute)
for protein in proteins:
protein_group.add(protein)
for water in waters:
solvent_group.add(water)
water_group.add(water)
for solvent in solvents:
solvent_group.add(solvent)
for ion in ions:
solvent_group.add(ion)
ion_group.add(ion)
if solute_group.nMolecules() > 0:
system.add(solute_group)
if protein_group.nMolecules() > 0:
system.add(protein_group)
if solvent_group.nMolecules() > 0:
system.add(solvent_group)
if water_group.nMolecules() > 0:
system.add(water_group)
if ion_group.nMolecules() > 0:
system.add(ion_group)
print("Number of solute molecules == %s" % solute_group.nMolecules())
print("Number of protein molecules == %s" % protein_group.nMolecules())
print("Number of ions == %s" % ion_group.nMolecules())
print("Number of water molecules == %s" % water_group.nMolecules())
print("Number of solvent molecules == %s" % solvent_group.nMolecules())
print(
"(solvent group is waters + ions + unidentified single-residue molecules)"
)
system.setProperty("space", space)
system.add(SpaceWrapper(Vector(0), all_group))
system.applyConstraints()
print("Returning the constructed system")
return system
hcl2_group = MoleculeGroup("HCl2", hcl2)
cff = InterCoulombFF("CoulombFF")
cff.add(hcl)
cff.add(hcl2)
print("Energy is %s : Should be about -10.9634 kcal mol-1" % cff.energy())
pottable = PotentialTable(hcl2_group)
cff.potential(pottable)
print("Potential is %s : Should be about [ -47.342 kcal mol-1, -15.380 kcal mol-1 ]" % \
(str(pottable.getTable(hcl2.number()).toVector())))
pol = PolariseCharges(hcl2_group)
system = System()
system.add(cff)
system.add(hcl2_group)
system.add(pol.selfEnergyFF())
system.add(pol)
system.applyConstraints()
hcl2 = system[hcl2.number()].molecule()
print(system.energies())
print(hcl2.property("induced_charge"))