Ejemplo n.º 1
0
        public SrmDocument ConvertToSmallMolecules(SrmDocument document, 
            ConvertToSmallMoleculesMode mode = ConvertToSmallMoleculesMode.formulas,
            bool invertCharges = false,
            bool ignoreDecoys=false)
        {
            if (mode == ConvertToSmallMoleculesMode.none)
                return document;
            var newdoc = new SrmDocument(document.Settings);
            var note = new Annotations(TestingConvertedFromProteomic, null, 1); // Mark this as a testing node so we don't sort it

            newdoc = (SrmDocument)newdoc.ChangeIgnoreChangingChildren(true); // Retain copied results

            foreach (var peptideGroupDocNode in document.MoleculeGroups)
            {
                if (!peptideGroupDocNode.IsProteomic)
                {
                    newdoc = (SrmDocument)newdoc.Add(peptideGroupDocNode); // Already a small molecule
                }
                else
                {
                    var newPeptideGroup = new PeptideGroup();
                    var newPeptideGroupDocNode = new PeptideGroupDocNode(newPeptideGroup,
                        peptideGroupDocNode.Annotations.Merge(note), peptideGroupDocNode.Name,
                        peptideGroupDocNode.Description, new PeptideDocNode[0],
                        peptideGroupDocNode.AutoManageChildren);
                    foreach (var mol in peptideGroupDocNode.Molecules)
                    {
                        var peptideSequence = mol.Peptide.Sequence;
                        // Create a PeptideDocNode with the presumably baseline charge and label
                        var precursorCharge = (mol.TransitionGroups.Any() ? mol.TransitionGroups.First().TransitionGroup.PrecursorCharge : 0) * (invertCharges ? -1 : 1);
                        var isotopeLabelType = mol.TransitionGroups.Any() ? mol.TransitionGroups.First().TransitionGroup.LabelType : IsotopeLabelType.light;
                        var moleculeCustomIon = ConvertToSmallMolecule(mode, document, mol, precursorCharge, isotopeLabelType);
                        var precursorCustomIon = moleculeCustomIon;
                        var newPeptide = new Peptide(moleculeCustomIon);
                        var newPeptideDocNode = new PeptideDocNode(newPeptide, newdoc.Settings, null, null,
                            null, null, mol.ExplicitRetentionTime, note, mol.Results, new TransitionGroupDocNode[0],
                            mol.AutoManageChildren);

                        foreach (var transitionGroupDocNode in mol.TransitionGroups)
                        {
                            if (transitionGroupDocNode.IsDecoy)
                            {
                                if (ignoreDecoys)
                                    continue;
                                throw new Exception("There is no translation from decoy to small molecules"); // Not L10N
                            }

                            if (transitionGroupDocNode.TransitionGroup.PrecursorCharge != Math.Abs(precursorCharge) ||
                                !Equals(isotopeLabelType, transitionGroupDocNode.TransitionGroup.LabelType))
                            {
                                // Different charges or labels mean different ion formulas
                                precursorCharge = transitionGroupDocNode.TransitionGroup.PrecursorCharge * (invertCharges ? -1 : 1);
                                isotopeLabelType = transitionGroupDocNode.TransitionGroup.LabelType;
                                precursorCustomIon = ConvertToSmallMolecule(mode, document, mol, precursorCharge, isotopeLabelType);
                            }

                            var newTransitionGroup = new TransitionGroup(newPeptide, precursorCustomIon, precursorCharge, isotopeLabelType);
                            // Remove any library info, since for the moment at least small molecules don't support this and it won't roundtrip
                            var resultsNew = RemoveTransitionGroupChromInfoLibraryInfo(transitionGroupDocNode);
                            var newTransitionGroupDocNode = new TransitionGroupDocNode(newTransitionGroup,
                                transitionGroupDocNode.Annotations.Merge(note), document.Settings,
                                null, null, transitionGroupDocNode.ExplicitValues, resultsNew, null,
                                transitionGroupDocNode.AutoManageChildren);
                            var mzShift = invertCharges ? 2.0 * BioMassCalc.MassProton : 0;  // We removed hydrogen rather than added
                            Assume.IsTrue((Math.Abs(newTransitionGroupDocNode.PrecursorMz + mzShift - transitionGroupDocNode.PrecursorMz) - Math.Abs(transitionGroupDocNode.TransitionGroup.PrecursorCharge * BioMassCalc.MassElectron)) <= 1E-5);

                            foreach (var transition in transitionGroupDocNode.Transitions)
                            {
                                double mass = 0;
                                var transitionCharge = transition.Transition.Charge * (invertCharges ? -1 : 1);
                                var ionType = IonType.custom;
                                CustomIon transitionCustomIon;
                                double mzShiftTransition = 0;
                                if (transition.Transition.IonType == IonType.precursor)
                                {
                                    ionType = IonType.precursor;
                                    transitionCustomIon = new DocNodeCustomIon(precursorCustomIon.Formula,
                                        string.IsNullOrEmpty(precursorCustomIon.Formula) ? precursorCustomIon.MonoisotopicMass : (double?) null,
                                        string.IsNullOrEmpty(precursorCustomIon.Formula) ? precursorCustomIon.AverageMass : (double?) null,
                                        SmallMoleculeNameFromPeptide(peptideSequence, transitionCharge));
                                    mzShiftTransition = invertCharges ? 2.0 * BioMassCalc.MassProton : 0;  // We removed hydrogen rather than added
                                }
                                else if (transition.Transition.IonType == IonType.custom)
                                {
                                    transitionCustomIon = transition.Transition.CustomIon;
                                    mass = transitionCustomIon.MonoisotopicMass;
                                }
                                else
                                {
                                    // TODO - try to get fragment formula?
                                    mass = BioMassCalc.CalculateIonMassFromMz(transition.Mz, transition.Transition.Charge);
                                    transitionCustomIon = new DocNodeCustomIon(mass, mass,// We can't really get at mono vs average mass from m/z, but for test purposes this is fine
                                        transition.Transition.FragmentIonName);
                                }
                                if (mode == ConvertToSmallMoleculesMode.masses_and_names)
                                {
                                    // Discard the formula if we're testing the use of mass-with-names (for matching in ratio calcs) target specification
                                    transitionCustomIon = new DocNodeCustomIon(transitionCustomIon.MonoisotopicMass, transitionCustomIon.AverageMass,
                                        transition.Transition.FragmentIonName);
                                }
                                else if (mode == ConvertToSmallMoleculesMode.masses_only)
                                {
                                    // Discard the formula and name if we're testing the use of mass-only target specification
                                    transitionCustomIon = new DocNodeCustomIon(transitionCustomIon.MonoisotopicMass, transitionCustomIon.AverageMass);
                                }

                                var newTransition = new Transition(newTransitionGroup, ionType,
                                    null, transition.Transition.MassIndex, transition.Transition.Charge * (invertCharges ? -1 : 1), null,
                                    transitionCustomIon);
                                if (ionType == IonType.precursor)
                                {
                                    mass = document.Settings.GetFragmentMass(transitionGroupDocNode.TransitionGroup.LabelType, null, newTransition, newTransitionGroupDocNode.IsotopeDist);
                                }
                                var newTransitionDocNode = new TransitionDocNode(newTransition, transition.Annotations.Merge(note),
                                    null, mass, transition.IsotopeDistInfo, null,
                                    transition.Results);
                                Assume.IsTrue((Math.Abs(newTransitionDocNode.Mz + mzShiftTransition - transition.Mz) - Math.Abs(transitionGroupDocNode.TransitionGroup.PrecursorCharge * BioMassCalc.MassElectron)) <= 1E-5, String.Format("unexpected mz difference {0}-{1}={2}", newTransitionDocNode.Mz , transition.Mz, newTransitionDocNode.Mz - transition.Mz)); // Not L10N
                                newTransitionGroupDocNode =
                                    (TransitionGroupDocNode)newTransitionGroupDocNode.Add(newTransitionDocNode);
                            }
                            if (newPeptideDocNode != null)
                                newPeptideDocNode = (PeptideDocNode)newPeptideDocNode.Add(newTransitionGroupDocNode);
                        }
                        newPeptideGroupDocNode =
                            (PeptideGroupDocNode)newPeptideGroupDocNode.Add(newPeptideDocNode);
                    }
                    newdoc = (SrmDocument)newdoc.Add(newPeptideGroupDocNode);
                }
            }

            // No retention time prediction for small molecules (yet?)
            newdoc = newdoc.ChangeSettings(newdoc.Settings.ChangePeptideSettings(newdoc.Settings.PeptideSettings.ChangePrediction(
                        newdoc.Settings.PeptideSettings.Prediction.ChangeRetentionTime(null))));

            return newdoc;
        }