R: Calculate the mass difference of modified peptides.

massShift {Peptides} | R Documentation

## Calculate the mass difference of modified peptides.

### Description

This function calculates the mass difference of peptides introduced by chemical modifications or heavy isotope labelling.

### Usage

    massShift(seq, label = "none", aaShift = NULL, monoisotopic = TRUE)

### Arguments

`seq` | An amino-acids sequence, in one letter code.
`label` | Set a predefined heavy isotope label. Accepts "none", "silac_13c", "silac_13c15n" and "15n". Overwrites input in `aaShift`.
`aaShift` | Define the mass difference in Dalton of given amino acids as a named vector. Use the amino acid one letter code as names and the mass shift in Dalton as values. N-terminal and C-terminal modifications can be defined by using "Nterm =" and "Cterm =", respectively.
`monoisotopic` | A logical value `'TRUE'` or `'FALSE'` indicating if monoisotopic weights of amino-acids should be used

### Source

For the predefined heavy isotope labels, compare:

- silac_13c Unimod 188

- silac_13c15n Unimod 259 and Unimod 267

- 15n Unimod 994, Unimod 995, Unimod 996 and Unimod 897

### Examples

    massShift("EGVNDNECEGFFSAR", label = "silac_13c")
    massShift("EGVNDNECEGFFSAR", aaShift = c(K = 6.020129, R = 6.020129))

[Package Peptides version 2.4.4 Index]