title: Tryptophan-contained peptide-functional nanomaterials as general spectrofluorometric reagents for enzyme.
abstract: By designing and coupling a functional peptide, Gly-Leu-Ala-Cys-Ser-Gly-Phe-Pro-Arg-Gly-Arg-Trp, which could be cleaved by thrombin at the site of Arg-Gly (R-G), to the surface of gold nanoparticles (Au-NPs), we propose a simple spectrofluorometry for thrombin (TRB) in this contribution. Experiments showed that the peptide coupled to the surface of Au-NPs in a Tris-HCl buffer at 37 degrees C could be cleaved, leaving the fluorescent fragment of Gly-Arg-Trp in the Au-NPs suspension. By centrifuging the suspension and measuring the fluorescence signals resulting from the Trp residue of Gly-Arg-Trp fragment in the supernatant, we found that the fluorescence intensity is proportional to thrombin concentrations in the range of 1-100 nM with the limit of the detection of 0.1 nM. Since there are a lot of enzymes that can hydrolyze peptide with special sequence, and novel nanomaterials that can bind with the tryptophan-contained peptide and understand centrifugation, this spectrofluorometric method is general and it is possible to develop a variety of detection method for target enzymes.
authors.affiliation: College of Chemistry and Chemical Engineering, CQKL-LRTA, Southwest University, Chongqing 400715, China.
authors.forename: Shu Jun
authors.initials: SJ
authors.lastname: Zhen
authors.forename: Yuan Fang
authors.initials: YF
authors.lastname: Li
authors.forename: Cheng Zhi
authors.initials: CZ
authors.lastname: Huang
authors.forename: Yun Fei
authors.initials: YF
authors.lastname: Long
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002138:Calibration; D002417:Cattle; D005453:Fluorescence; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007202:Indicators and Reagents / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence; D013917:Thrombin / Q000737:chemistry / Q000378:metabolism*; D014364:Tryptophan / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D007202:Indicators and Reagents; D009842:Oligopeptides; D006046:Gold; D014364:Tryptophan; D013917:Thrombin