title: Probing the caspase-3 active site by fluorescence lifetime measurements.
abstract: The active site of an apoptotic enzyme caspase-3 was characterized by measuring the intrinsic fluorescence of two tryptophan residues. Temperature dependence of the intrinsic fluorescence, the energy homotransfer between the tryptophan residues, and the fluorescence quenching by tetrapeptide inhibitors were investigated by the fluorescence lifetime measurements. It has been observed that the fluorescence lifetimes of caspase-3 in complex with inhibitors were significantly shortened by the electron transfer process.
authors.affiliation: Division of Molecular Life Sciences and Department of Chemistry, Ewha Womans University, Seoul, South Korea.
authors.forename: Minjoung
authors.initials: M
authors.lastname: Kyoung
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kim
authors.forename: Hee-Young
authors.initials: HY
authors.lastname: Seok
authors.forename: Il-Sun
authors.initials: IS
authors.lastname: Park
authors.forename: Minyung
authors.initials: M
authors.lastname: Lee
mesh_terms: D053148:Caspase 3; D020169:Caspases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D007700:Kinetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013050:Spectrometry, Fluorescence / Q000379:methods; D014364:Tryptophan / Q000032:analysis
chemical_list: D015853:Cysteine Proteinase Inhibitors; D011994:Recombinant Proteins; D014364:Tryptophan; D053148:Caspase 3; D020169:Caspases