title: Rearrangement of tryptophan residues in caspase-3 active site upon activation.
abstract: Caspase-3, one of the major apoptotic proteins, is a cysteine protease and exists as an inactive zymogen in healthy cells. In this study, the dynamic nature of the rearrangements of two tryptophan residues (Trp 206 and Trp 214) in the active sites of caspase-3 during the activation was analyzed by measuring the fluorescence lifetimes. Significant changes in the lifetime occurred upon activation by the specific cleavage. In addition, two mutant proteins that have only one tryptophan residue also showed the similar changes. These data indicate that the activation of caspase-3 resulted in the reorganization of both tryptophan residues.
authors.affiliation: Research Center for Proteineous Materials and Department of Bio-Materials Engineering, Chosun University, Seosuk-Dong, Dong-Gu, Gwangju 501-759, South Korea. parkis@chosun.ac.kr
authors.forename: Il-Seon
authors.initials: IS
authors.lastname: Park
authors.forename: Hyung Rang
authors.initials: HR
authors.lastname: Moon
authors.forename: Heeyoung
authors.initials: H
authors.lastname: Seok
authors.forename: Minyung
authors.initials: M
authors.lastname: Lee
mesh_terms: D001665:Binding Sites; D053148:Caspase 3; D020169:Caspases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D005453:Fluorescence; D007700:Kinetics; D009154:Mutation / Q000235:genetics; D013997:Time Factors; D014364:Tryptophan / Q000235:genetics / Q000378:metabolism*
chemical_list: D014364:Tryptophan; D053148:Caspase 3; D020169:Caspases; D003545:Cysteine