reference peptide database (post-translational products)

Question

[gtrwst9]

Many databases when referring to a peptide give UniProt IDs, but these are too general and can refer to many cleavage products of a single gene. Is there a database which gives IDs for single peptides and has all (or most) of them? They could even be restricted to be bioactive. This would be of great help for the open Wikidata project..