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wrTopDownFrag (version 1.0.4)

Internal Fragment Identification from Top-Down Mass Spectrometry

Description

Top-Down mass spectrometry aims to identify entire proteins as well as their (post-translational) modifications or ions bound (eg Chen et al (2018) ). The pattern of internal fragments (Haverland et al (2017) ) may reveal important information about the original structure of the proteins studied (Skinner et al (2018) and Li et al (2018) ). However, the number of possible internal fragments gets huge with longer proteins and subsequent identification of internal fragments remains challenging, in particular since the the accuracy of measurements with current mass spectrometers represents a limiting factor. This package attempts to deal with the complexity of internal fragments and allows identification of terminal and internal fragments from deconvoluted mass-spectrometry data.

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Version

Install

install.packages('wrTopDownFrag')

Monthly Downloads

152

Version

1.0.4

License

GPL-3

Maintainer

Wolfgang Raffelsberger

Last Published

April 21st, 2025

Functions in wrTopDownFrag (1.0.4)

.NtermPepCut

Make Named Character Vector Of Sequential C-Terminal Fragments
.multMatByColNa

Multiply Values Of Matrix By Its Colnames And Sum By Row
.chColNa

Check Column Names from Matrix Or data.frame
.chargeCatchingAA

Cite Charge Catching Amino-Acids
.evalIsoFra

Evaluate Selected Lines Of PepTab
.countModif

Count For All Proteins The Occurance Of Modification Types
makeFragments

Make Terminal And Internal Fragments From Proteins
.prefFragPattern

Return data.frame with pattern of perferential fragmentation sites
.singleSpecModif

Add Single Specific Modifications
fragmentSeq

Fragment Protein Or Peptide Sequence
identifFixedModif

Identify Fixed Modifications
scoreChargeCatch

Scoring Of Charge Catching Potential For Peptides
scoreProteinFragments

Scoring Of Identifications (For Multi-Protein Queries)
scoreFragments

Scoring For Single Protein : Individual Components
scorePrefFrag

Identifcation and scoring of preferential cuting sites
identifVarModif

Idenitfy Variable Modifications
randMassByMut

Make decoy mass by full randomization
randMassByStochastic

Make Decoy Mass By Full Randomization
identifyPepFragments

Identify terminal and internal protein/peptide-fragments as matches to experimental MS-peaks
.termPepCut

Make Named Character Vector Of Sequential Terminal Fragments
plotMgfLike

Draw simplified (deconvoluted) spectrum of mgf type and highlight peaks with matches found to theoretical data
plotNTheor

Plot the number of theoretical random fragments
modifFragmTabOutput

Change fragment identification output format (for biologists)
plotFragmLoc

Plot Identified Fragments Relative To Their Location
evalIsoFragm

Evaluate Selected Lines Of PepTab (iso-mass) For Preferential Cutting Sites
plotPrefFragPat

plot preferential fragmenation pattern Plot preferential fragmenation pattern equivalent to Fig 1b of Haverland et al 2017 (J Am Soc Mass Spectrom)
corInDelShift

Corrective Values For Random Sequences For In/Dels
checkModTy

Check & complete mixed of variable and fixed modifications
.CtermPepCut

Make Named Character Vector Of Sequential C-Terminal Fragments
combinateAllAndSum

Full Combinatorial And Cumulative Values
AAfragSettings

Settings For AA Fragmentation
combinatIntTable

Planing For Making All Multiplicative Combinations
addMassModif

Add Modifications To Peptide Mass
countChildrenParent

Identify Children/Parent Settings As a+b=c
countPotModifAAs

Make Table With Counts of Potential Modification Sites
corMutShift

Corrective Values For Random Sequences For Mutations
.exNamesTyDeList

Reorganize List Of Peptide Fragments To Matrix
.checkModTy

Check Modification Type
.parCombinateAllAndSum

Multiprocessor Version For Full Combinatorial And Cumulative Values
.countLET

Count Letters