Exemplo n.º 1
0
 // Returns molecule mass (or massH, for peptides)
 public TypedMass GetMoleculeMass()
 {
     Assume.IsTrue(Transition.IsCustom() || MzMassType.IsMassH());
     return(Transition.IsCustom()
         ? Transition.Adduct.MassFromMz(Mz, MzMassType)
         : new TypedMass(SequenceMassCalc.GetMH(Mz, Transition.Charge), MzMassType));
 }
Exemplo n.º 2
0
        public double GetMassI(int massIndex, int?decoyMassShift = null)
        {
            // Return the original monoisotopic mass + H, if requested to maintain an exact match.
            if (massIndex == 0 && !decoyMassShift.HasValue)
            {
                return(_monoisotopicMass);
            }
            // Otherwize use the charge to convert from the peak center m/z values
            double shift = SequenceMassCalc.GetPeptideInterval(decoyMassShift);    // Correct for shift applied to the distribution

            return(_isMassH ? SequenceMassCalc.GetMH(ExpectedPeaks[MassIndexToPeakIndex(massIndex)].Mz - shift, _charge) : BioMassCalc.CalculateIonMassFromMz(ExpectedPeaks[MassIndexToPeakIndex(massIndex)].Mz - shift, _charge));
        }
Exemplo n.º 3
0
        private MoleculeMasses GetCrosslinkMasses(SrmSettings settings)
        {
            var predictDocNode = MakeTransitionGroupWithAllPossibleChildren(settings, TargetInfoObj.TransitionGroupDocNode.LabelType);
            TransitionGroupDocNode matchDocNode;

            if (Equals(TargetInfoObj.TransitionGroupDocNode.LabelType, TargetInfoObj.SpectrumLabelType))
            {
                matchDocNode = predictDocNode;
            }
            else
            {
                matchDocNode = MakeTransitionGroupWithAllPossibleChildren(settings, TargetInfoObj.SpectrumLabelType);
            }

            var matchTransitions = matchDocNode.Transitions.ToDictionary(child => child.Key(matchDocNode));


            var predictFragments = new List <MatchedFragmentIon>();
            var matchFragments   = new List <MatchedFragmentIon>();

            foreach (var predictedTransition in predictDocNode.Transitions)
            {
                var key = predictedTransition.Key(null);
                TransitionDocNode matchTransition;
                if (!matchTransitions.TryGetValue(key, out matchTransition))
                {
                    continue;
                }

                var    complexFragmentIonName = predictedTransition.ComplexFragmentIon.GetName();
                var    ionType      = DecideIonType(complexFragmentIonName);
                string fragmentName = predictedTransition.ComplexFragmentIon.GetFragmentIonName();
                var    predictedIon = new MatchedFragmentIon(ionType, predictFragments.Count + 1,
                                                             predictedTransition.Transition.Adduct, fragmentName, predictedTransition.Losses,
                                                             predictedTransition.Mz)
                                      .ChangeComplexFragmentIonName(complexFragmentIonName);
                predictFragments.Add(predictedIon);
                matchFragments.Add(predictedIon.ChangePredictedMz(matchTransition.Mz));
            }

            var matchMasses = new IonMasses(
                SequenceMassCalc.GetMH(matchDocNode.PrecursorMz, matchDocNode.PrecursorAdduct,
                                       MassType.MonoisotopicMassH), IonTable <TypedMass> .EMPTY)
                              .ChangeKnownFragments(matchFragments);
            var predictMasses = new IonMasses(
                SequenceMassCalc.GetMH(predictDocNode.PrecursorMz, predictDocNode.PrecursorAdduct,
                                       MassType.MonoisotopicMassH), IonTable <TypedMass> .EMPTY)
                                .ChangeKnownFragments(predictFragments);

            return(new MoleculeMasses(predictDocNode.PrecursorMz, matchMasses).ChangePredictIonMasses(predictMasses));
        }
Exemplo n.º 4
0
        public TypedMass GetMassI(int massIndex, int?decoyMassShift = null)
        {
            // Return the original monoisotopic mass + H, if requested to maintain an exact match.
            if (massIndex == 0 && !decoyMassShift.HasValue)
            {
                return(_monoisotopicMass);
            }
            // Otherwize use the charge to convert from the peak center m/z values
            double shift = SequenceMassCalc.GetPeptideInterval(decoyMassShift);    // Correct for shift applied to the distribution

            // ReSharper disable ImpureMethodCallOnReadonlyValueField
            return(_monoisotopicMass.IsMassH() ?
                   new TypedMass(SequenceMassCalc.GetMH(ExpectedPeaks[MassIndexToPeakIndex(massIndex)].Mz - shift, _adduct.AdductCharge), _monoisotopicMass.MassType) :
                   _adduct.MassFromMz(ExpectedPeaks[MassIndexToPeakIndex(massIndex)].Mz - shift, _monoisotopicMass.MassType));
            // ReSharper restore ImpureMethodCallOnReadonlyValueField
        }
Exemplo n.º 5
0
 public double GetIonMass()
 {
     return(Transition.IsCustom()
         ? BioMassCalc.CalculateIonMassFromMz(Mz, Transition.Charge)
         : SequenceMassCalc.GetMH(Mz, Transition.Charge));
 }
Exemplo n.º 6
0
        public static Adduct CalcProductCharge(TypedMass productPrecursorMass,
                                               int?productZ,
                                               Adduct precursorCharge,
                                               IList <IonType> acceptedIonTypes,
                                               IonTable <TypedMass> productMasses,
                                               IList <IList <ExplicitLoss> > potentialLosses,
                                               double productMz,
                                               double tolerance,
                                               MassType massType,
                                               MassShiftType massShiftType,
                                               out IonType?ionType,
                                               out int?ordinal,
                                               out TransitionLosses losses,
                                               out int massShift)
        {
            // Get length of fragment ion mass array
            int len = productMasses.GetLength(1);

            // Check all possible ion types and offsets
            double?minDelta = null;
            double?minFragmentMass = null, maxFragmentMass = null, maxLoss = null;

            if (massShiftType == MassShiftType.none)
            {
                if (!productZ.HasValue)
                {
                    minFragmentMass = productMz - tolerance;
                }
                else
                {
                    minFragmentMass = SequenceMassCalc.GetMH(productMz - tolerance, productZ.Value);
                    maxFragmentMass = SequenceMassCalc.GetMH(productMz + tolerance, productZ.Value);
                }
            }

            var              bestCharge    = Adduct.EMPTY;
            IonType?         bestIonType   = null;
            int?             bestOrdinal   = null;
            TransitionLosses bestLosses    = null;
            int              bestMassShift = 0;

            // Check to see if it is the precursor
            foreach (var lossesTrial in TransitionGroup.CalcTransitionLosses(IonType.precursor, 0, massType, potentialLosses))
            {
                var productMass = productPrecursorMass;
                if (lossesTrial != null)
                {
                    productMass -= lossesTrial.Mass;
                    maxLoss      = Math.Max(maxLoss ?? 0, lossesTrial.Mass);
                }
                int potentialMassShift;
                int nearestCharge;
                var charge = CalcProductCharge(productMass, productZ, productMz, tolerance, false, precursorCharge,
                                               massShiftType, out potentialMassShift, out nearestCharge);
                if (Equals(charge, precursorCharge))
                {
                    double potentialMz = SequenceMassCalc.GetMZ(productMass, charge) + potentialMassShift;
                    double delta       = Math.Abs(productMz - potentialMz);

                    if (CompareIonMatch(delta, lossesTrial, potentialMassShift, minDelta, bestLosses, bestMassShift) < 0)
                    {
                        bestCharge    = charge;
                        bestIonType   = IonType.precursor;
                        bestOrdinal   = len + 1;
                        bestLosses    = lossesTrial;
                        bestMassShift = potentialMassShift;

                        minDelta = delta;
                    }
                }
            }

            if (maxLoss.HasValue)
            {
                maxFragmentMass += maxLoss.Value;
            }

            var categoryLast = -1;

            foreach (var typeAccepted in GetIonTypes(acceptedIonTypes))
            {
                var type     = typeAccepted.IonType;
                var category = typeAccepted.IonCategory;

                // Types have priorities.  If changing type category, and there is already a
                // suitable answer stop looking.
                if (category != categoryLast && minDelta.HasValue && MatchMz(minDelta.Value, tolerance))
                {
                    break;
                }
                categoryLast = category;

                // The peptide length is 1 longer than the mass array
                for (int ord = len; ord > 0; ord--)
                {
                    int offset          = Transition.OrdinalToOffset(type, ord, len + 1);
                    var productMassBase = productMasses[type, offset];
                    // Until below the maximum fragment mass no possible matches
                    if (maxFragmentMass.HasValue && productMassBase > maxFragmentMass.Value)
                    {
                        continue;
                    }
                    // Once below the minimum fragment mass no more possible matches, so stop
                    if (minFragmentMass.HasValue && productMassBase < minFragmentMass.Value)
                    {
                        break;
                    }

                    foreach (var lossesTrial in TransitionGroup.CalcTransitionLosses(type, offset, massType, potentialLosses))
                    {
                        // Look for the closest match.
                        var productMass = productMassBase;
                        if (lossesTrial != null)
                        {
                            productMass -= lossesTrial.Mass;
                        }
                        int potentialMassShift;
                        int nearestCharge;
                        var chargeFound = CalcProductCharge(productMass, productZ, productMz, tolerance, false, precursorCharge,
                                                            massShiftType, out potentialMassShift, out nearestCharge);
                        if (!chargeFound.IsEmpty)
                        {
                            var    charge      = chargeFound;
                            double potentialMz = SequenceMassCalc.GetMZ(productMass, charge) + potentialMassShift;
                            double delta       = Math.Abs(productMz - potentialMz);
                            if (CompareIonMatch(delta, lossesTrial, potentialMassShift, minDelta, bestLosses, bestMassShift) < 0)
                            {
                                bestCharge    = charge;
                                bestIonType   = type;
                                bestOrdinal   = ord;
                                bestLosses    = lossesTrial;
                                bestMassShift = potentialMassShift;

                                minDelta = delta;
                            }
                        }
                    }
                }
            }

            ionType   = bestIonType;
            ordinal   = bestOrdinal;
            losses    = bestLosses;
            massShift = bestMassShift;
            return(bestCharge);
        }