{"id":678,"sequence":"GPPGSAGAPGKDGLNGLPGPIGPPGPR","proforma":"[Oxidation]^4?GPPGSAGAPGKDGLNGLPGPIGPPGPR","modifications":[{"name":"Oxidation","count":4,"n_term":false,"unimod":35,"position":null,"residues":"P"}],"mods_ambiguous":false,"neutral_mass":2453.2298998937003,"mh":2454.23718,"url":"https://msipep.com/peptide/678/"}