| PTMods-package | Managing amino acid modifications for mass spectrometry in R. |
| .convertAnnotation | Convert sequences from one annotation style to another |
| addFixedModifications | Add fixed modifications |
| addModifications | Add fixed and variable modifications to peptide sequences |
| addVariableModifications | Add variable modifications |
| aminoacids | Amminoacids data set. |
| combineModifications | Combines consecutive modifications on amino acids in peptide sequences. |
| convertAnnotation | Convert sequences from one annotation style to another |
| elements | Elements data set. |
| getCanonicalSequence | Get canonical sequence from any peptidoform |
| getModificationsCounts | Extract modification counts from one or more peptide sequences |
| modifications | Modifications data set. |
| PTMods | Managing amino acid modifications for mass spectrometry in R. |