title: Supramolecular Chemistry-Assisted Electrochemical Method for the Assay of Endogenous Peptidylarginine Deiminases Activities.
abstract: Peptidylarginine deiminase 4 (PAD4) is the only isoform of PADs located within the cell nucleus, which has been known to be related to several human diseases. In this work, we have proposed an electrochemical method for the assay of endogenous PAD4 activities as well as the studies of PAD4 inhibitors by making use of the supramolecular chemistry-assisted signal labeling. Specifically, peptide probes P1 and P2, which separately contain cysteine residues and tripeptides FGG (Phe-Gly-Gly), can be self-assembled onto the surface of the gold electrode and silver nanoparticles, respectively. In the meantime, the peptide probes can be connected together through cucurbit[8]uril-mediated host-guest interaction. Nevertheless, after trypsin-catalyzed digestion, FGG at the N-terminal of P1 will be removed from the electrode surface, thereby inhibiting the connection of P1 and P2. Since PAD4 catalyzes the citrullination of arginine residue within P1, trypsin-catalyzed digestion of P1 can be prohibited by the addition of PAD4. Consequently, an obvious change of the electrochemical response can be obtained from the silver nanoparticles (AgNPs) immobilized on the electrode surface. Experimental results have shown that our method can display an improved sensitivity and specificity for both PAD4 assay and inhibitor screening, which may effectively trace endogenous PAD4 and the inhibitors in the cancer cells. Therefore, our method may have great potential for the diagnosis and treatment of PAD4-related diseases in the future.
authors.affiliation: Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University , Shanghai 200444, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University , Shanghai 200444, P. R. China.
authors.forename: Lili
authors.initials: L
authors.lastname: Yang
authors.affiliation: Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University , Shanghai 200444, P. R. China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Nanjing Medical University , Nanjing 210029, P. R. China.
authors.forename: Yucai
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Oncology, The First Affiliated Hospital of Nanjing Medical University , Nanjing 210029, P. R. China.
authors.forename: Yongmei
authors.identifier: 0000-0001-7240-0941
authors.initials: Y
authors.lastname: Yin
mesh_terms: D001120:Arginine; D002956:Citrulline; D055664:Electrochemical Techniques; D006801:Humans; D006867:Hydrolases; D009842:Oligopeptides; D000076342:Protein-Arginine Deiminases
chemical_list: D009842:Oligopeptides; C043963:phenylalanyl-glycyl-glycine; D002956:Citrulline; D001120:Arginine; D006867:Hydrolases; D000076342:Protein-Arginine Deiminases
keywords: cucurbit[8]uril; electrochemical assay; inhibitor; peptidylarginine deiminase 4; silver nanoparticles; trypsin