title: Label-free fluorometric method for monitoring conformational flexibility of laccase based on a selective laccase sensor.
abstract: A facile and selective fluorescence sensor for laccase determination has been proposed depending on the interaction between 3-azidocoumarin and trametes versicolor (Tv) laccase in this paper. The azido group of 3-azidocoumarin that is electron-rich α-nitrogen can directly interact with histidines that coordinate to three copper sites through hydrogen bonds and forms a new complex, which decreases the electron-donating ability of the azido group, leading to enhance the fluorescence intensity of the sensing system. Also, other common proteins have no significant interference for the proposed laccase sensor. Additionally, the proposed fluorescence sensor is extended to demonstrate the conformational flexibility of Tv laccase by the urea denaturant. A good consistency of the results obtained with the presented laccase sensor and CD spectra is performed. Furthermore, the relationship between the catalytic activity and the unfolding percentage of the unfolded Tv laccase through the proposed laccase sensor is also elucidated well.
authors.affiliation: Institute for Quality & Safety and Standards of Agricultural Products Research, Jiangxi Academy of Agricultural Sciences , Nanchang, Jiangxi, 330200, China.
authors.forename: Suyan
authors.initials: S
authors.lastname: Qiu
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Lin
authors.forename: Yaomin
authors.initials: Y
authors.lastname: Zhou
authors.forename: Ruili
authors.initials: R
authors.lastname: Li
authors.forename: Jinyan
authors.initials: J
authors.lastname: Zhang
authors.forename: Dawen
authors.initials: D
authors.lastname: Zhang
authors.forename: Linguang
authors.initials: L
authors.lastname: Luo
authors.forename: Longhua
authors.initials: L
authors.lastname: Guo
authors.forename: Bin
authors.initials: B
authors.lastname: Qiu
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
mesh_terms: D001386:Azides / Q000378:metabolism*; D001681:Biological Assay; D015374:Biosensing Techniques / Q000379:methods*; D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry; D003374:Coumarins / Q000378:metabolism*; D005456:Fluorescent Dyes; D005470:Fluorometry / Q000379:methods*; D042845:Laccase / Q000032:analysis* / Q000378:metabolism; D055454:Trametes / Q000201:enzymology*
chemical_list: D001386:Azides; D003374:Coumarins; D005456:Fluorescent Dyes; D003300:Copper; D042845:Laccase