title: Sensitive and selective detection of thrombin by using a cyclic peptide as affinity ligand.
abstract: Here we describe a sensitive assay for thrombin by using a high binding-affinity cyclic peptide against thrombin as affinity ligand. The cyclic peptide is immobilized on the magnetic beads or microplates to selectively capture thrombin. The enriched thrombin then catalyzes the cleavage of a substrate of thrombin to a detectable product. The detection of thrombin is finally achieved by measuring the generated product. This assay enables the detection of thrombin at tens fM in 100 µL of sample solution when fluorogenic substrate was applied, while detection limits reached pM level when chromogenic substrate was used. Thrombin in plasma sample can be detected with this assay. This cyclic peptide affinity ligand shows potentials for thrombin analysis in other detection formats.
authors.affiliation: Research Institute of Environmental Science, College of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China. Electronic address: chemzhaoq@hotmail.com.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Research Institute of Environmental Science, College of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
mesh_terms: D015374:Biosensing Techniques; D005456:Fluorescent Dyes; D006801:Humans; D008024:Ligands; D010456:Peptides, Cyclic / Q000737:chemistry*; D013917:Thrombin / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D005456:Fluorescent Dyes; D008024:Ligands; D010456:Peptides, Cyclic; D013917:Thrombin
keywords: Affinity ligand; Cyclic peptide; Enzyme reaction; Protein detection; Thrombin