title: Novel biosensor system model based on fluorescence quenching by a fluorescent streptavidin and carbazole-labeled biotin.
abstract: In the present study, a novel molecular biosensor system model was designed by using a couple of the fluorescent unnatural mutant streptavidin and the carbazole-labeled biotin. BODIPY-FL-aminophenylalanine (BFLAF), a fluorescent unnatural amino acid was position-specifically incorporated into Trp120 position of streptavidin by four-base codon method. On the other hand, carbazole-labeled biotin was synthesized as a quencher for the fluorescent Trp120BFLAF mutant streptavidin. The fluorescence of fluorescent Trp120BFLAF mutant streptavidin was decreased as we expected when carbazole-labeled biotin was added into the mutant streptavidin solution. Furthermore, the fluorescence decrease of Trp120BFLAF mutant streptavidin with carbazole-labeled biotin (100 nM) was recovered by the competitive addition of natural biotin. This result demonstrated that by measuring the fluorescence quenching and recovery, a couple of the fluorescent Trp120BFLAF mutant streptavidin and the carbazole-labeled biotin were successfully applicable for quantification of free biotin as a molecular biosensor system. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Innovation Research Centre of Acupuncture Combined with Medicine, Shaanxi University of Chinese Medicine, Xi'an-Xianyang New Ecomic Zone, Shaanxi Province, 712046, China. jater0228@outlook.com.
authors.forename: Xianwei
authors.identifier: 0000-0001-6337-5326
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Graduate School of Science and Engineering for Research, University of Toyama, 3190 Gofuku, Toyama, 930-8555, Japan. hshinoha@eng.u-toyama.ac.jp.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shinohara
authors.affiliation: Graduate School of Science and Engineering for Research, University of Toyama, 3190 Gofuku, Toyama, 930-8555, Japan.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Miyatake
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Hohsaka
mesh_terms: D015374:Biosensing Techniques; D001710:Biotin / Q000737:chemistry* / Q000378:metabolism; D002227:Carbazoles / Q000737:chemistry* / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry; D008958:Models, Molecular; D009154:Mutation; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D019809:Streptavidin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014364:Tryptophan / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D002227:Carbazoles; D005456:Fluorescent Dyes; C041514:carbazole; D001710:Biotin; D014364:Tryptophan; D019809:Streptavidin
keywords: carbazole-labeled biotin; fluorescence quenching; fluorescence recovery; fluorescent unnatural mutant streptavidin; four-base codon method; molecular biosensor