Amperometric Detection of Apoptosis by using p‐Methoxyaniline‐Conjugated Substrate for Caspase‐3

• Published in: ChemElectroChem Vol. 4; no. 4; pp. 941 - 946
• Main Authors: Sixiang, Sun, Inoue, Kumi Y., Shiomoto, Shusaku, Takano, Shinichiro, Ino, Kosuke, Shiku, Hitoshi, Matsue, Tomokazu
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.04.2017
• Subjects: amperometric detection; Apoptosis; biosensing; Biotechnology; caspase-3; Electrical measurements; Inertia; peptide substrate; Releasing; Saline; Substrates; Toxicity
• ISSN: 2196-0216; 2196-0216
• DOI: 10.1002/celc.201600700

This manuscript reports on a novel substrate for the amperometric detection of cellular apoptosis, Asp‐Glu‐Val‐Asp‐p‐methoxyaniline (DEVD‐pMA). This substrate showed electrochemical inertia from −0.2 to 0.7 V versus Ag/AgCl in phosphate‐buffered saline (PBS), but was cleaved by caspase‐3, releasing pMA, which was detected with cyclic voltammetry and chronoamperometry. Compared with p‐aminophenol (pAP), pMA showed lower toxicity to the human hepatocellular carcinoma cell line (HepG2) and higher stability in PBS. By using this substrate, we successfully detected caspase‐3 in the range of 0.31–2.5×10−2 units/mL and cellular apoptosis in HepG2 cells by using simple amperometry without cell lysis. This work will help to develop a simple method for the electrochemical monitoring of apoptosis, which can be applied in biological research and drug development. Electric current tells cell apoptosis: A novel caspase‐3 substrate, Asp‐Glu‐Val‐Asp‐p‐methoxyaniline (DEVD‐pMA), is developed for simple amperometric detection of cellular apoptosis. This substrate is cleaved by caspase‐3, releaseing the pMA molecule, which can be detected with amperometry. By using DEVD‐pMA, caspase‐3 is successfully detected in the range of 0.31–2.5×10−2 units/mL. Cellular apoptosis in HepG2 cells is also detected through simple amperometry without cell lysis.