PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 22052779-4 2012 We observed a progressive increase of the quenching effect of the nitroxyl radical on the fluorescence of the N-terminal tryptophan as TOAC replaces the Aib residue at positions 13, 8, and 4, respectively. Tryptophan 121-131 ANIB1 Homo sapiens 153-156