title: Sensing lymphoma cells based on a cell-penetrating/apoptosis-inducing/electron-transfer peptide probe.
abstract: To electrochemically sense lymphoma cells (U937), we fabricated a multifunctional peptide probe that consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. Electron-transfer peptides derive from cysteine residue combined with the C-terminals of four tyrosine residues (Y4). A peptide whereby Y4C is bound to the C-terminals of protegrin 1 (RGGRLCYCRRRFCVCVGR-NH2) is known to be an apoptosis-inducing agent against U937 cells, and is referred to as a peptide-1 probe. An oxidation response of the peptide-1 probe has been observed due to a phenolic hydroxyl group, and this response is decreased by the uptake of the peptide probe into the cells. To improve the cell membrane permeability against U937 cells, the RGGR at the N-terminals of the peptide-1 probe was replaced by RRRR (peptide-2 probe). In contrast, RNRCKGTDVQAWY4C (peptide-3 probe), which recognizes ovalbumin, was constructed as a control. Compared with the other probes, the change in the peak current of the peptide-2 probe was the greatest at low concentrations and occurred in a short amount of time. Therefore, the cell membrane permeability of the peptide-2 probe was increased based on the arginine residues and the apoptosis-inducing peptides. The peak current was linear and ranged from 100 to 1000 cells/ml. The relative standard deviation of 600 cells/ml was 5.0% (n = 5). Furthermore, the membrane permeability of the peptide probes was confirmed using fluorescent dye.
authors.affiliation: Maebashi Institute of Technology, Gunma 371-0816, Japan. Electronic address: kzsuga@maebashi-it.ac.jp.
authors.forename: Kazuharu
authors.initials: K
authors.lastname: Sugawara
authors.affiliation: Maebashi Institute of Technology, Gunma 371-0816, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Shinohara
authors.affiliation: Maebashi Institute of Technology, Gunma 371-0816, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kadoya
authors.affiliation: Department of Environmental Biology and Chemistry, Graduate School of Science and Engineering for Research, University of Toyama, Toyama 930-8555, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Kuramitz
mesh_terms: D000595:Amino Acid Sequence; D057846:Cell-Penetrating Peptides / Q000737:chemistry / Q000378:metabolism*; D004566:Electrodes; D004579:Electron Transport; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D008223:Lymphoma / Q000378:metabolism* / Q000473:pathology; D020298:U937 Cells
chemical_list: D057846:Cell-Penetrating Peptides; D005456:Fluorescent Dyes
keywords: Apoptosis; Cell-penetrating peptide; Oligoarginine; Tyrosine-rich peptide; U937 cell