IPTMnet Get Proteoforms

Get proteoform records for a protein from iPTMnet. Proteoforms represent specific combinations of PTM sites on a protein, as defined by the PRO ontology. Each proteoform has a PRO ID, modified sites, the responsible enzyme (if known), source database, and PubMed references. Useful for understanding which specific PTM combinations have been experimentally observed. Use with UniProt accession (e.g., P04637 for TP53).