add_mod_symbol {MSnID} | R Documentation |
Given the provided modification mass, annotates its position within the peptide sequence with provided symbol.
add_mod_symbol(object, mod_mass, symbol)
object |
An instance of class "MSnID". |
mod_mass |
(string) modification mass. Must match exactly one of the masses in
|
symbol |
(string) character that annotates the position of the modification |
Returns MSnID object with new or modified peptide_mod
column.
The column contains peptide sequence with amino acid
modifications annotated with symbols.
In current implementation the method can not distinguish modifications with the same mass, but different amino acid specificity as different modifications.
Vladislav A Petyuk vladislav.petyuk@pnnl.gov
m <- MSnID(".") mzids <- system.file("extdata","phospho.mzid.gz",package="MSnID") m <- read_mzIDs(m, mzids) # to know the present mod masses report_mods(m) # TMT modification m <- add_mod_symbol(m, mod_mass="229.1629", symbol="#") # alkylation m <- add_mod_symbol(m, mod_mass="57.021463735", symbol="^") # phosphorylation m <- add_mod_symbol(m, mod_mass="79.966330925", symbol="*") # show the mapping head(unique(subset(psms(m), select=c("modification", "peptide_mod")))) # clean-up cache unlink(".Rcache", recursive=TRUE)