Hello,

I am having trouble finding a method to collapse log fold change data of peptides determined from mass spec that have the same peptide sequence but differ in the number of PTM events. An example is attached below,

TMT16plex-SATDGNTST(Phospho)TPPTS(Phospho)AK(TMT16plex)

TMT16plex-SATDGNTST(Phospho)TPPTSAK(TMT16plex)

In this case both of these sequences have their own log fold change data, but we are having trouble relating the log FC data of the first Threonine to each other.

Statistical information we have include Expect-values, p-values and nPSMs used.

I've searched in literature but am failing to find a similar case, was wondering if anyone had any ideas.