Electrochemical Proteolytic Beacon for Detection of Matrix Metalloproteinase Activities

Abstract

This communication describes a novel method for detecting matrix metalloproteinase-7 activity using a peptide substrate labeled with a ferrocene reporter. The substrate serves as a selective "electrochemical proteolytic beacon" (EPB) for this metalloproteinase. The EPB is immobilized on a gold electrode surface to enable "on-off" electrochemical signaling capability for uncleaved and cleaved events. The EPB is efficiently and selectively cleaved by MMP-7 as measured by the rate of decrease in redox current of ferrocene. Direct transduction of a signal corresponding to peptide cleavage events into an electronic signal thus provides a simple, sensitive route for detecting the MMP activity. The new method allows for identification of the activity of MMP-7 in concentrations as low as 3.4 pM. The concept can be extended to design a multiple peptide substrate labeled with different electroactive reporters for assaying multiple MMPs activities.

Designer Peptides: Attempt to Control Peptide Structure by Exploiting Ferrocene as a Scaffold

“…In addition, Fc-peptide conjugates are being exploited as bioorganometallic sensors to detect protein-binding interactions [38] or even enzymatic activity. [39] Whereas this Microreview does not specifically address this interesting application of Fcpeptide conjugates, one has to recognize the importance of this class of compounds in biosensing. Briefly, the Fc group acts as the redox probe providing an electrochemical readout of a target analyte interacting with the peptide recognition sequence.…”

A review on electronic bio-sensing approaches based on non-antibody recognition elements

“…41 Herein, peptides were immobilized on Au electrodes via self-assembly and cleaved in the presence of MMP-7 ( Fig. 8a), resulting in detectable current changes.…”

Design and Application of Multi-functional Electrogenerated Chemiluminescence Imaging Analyzer

“…In the absence of MMP-7, a high ECL signal can be obtained at the ECL biosensor in the presence of TPA. In the presence of MMP-7, MMP-7 can specifically cleave the peptide and then lead the partly Ru1-peptide to leave the electrode surface, 29 resulting in the decrease of the ECL intensity obtained from the resulted electrode in the presence of TPA. Figure 4(B) shows the ECL imaging of different ECL biosensors in the presence of different concentrations of MMP-7.…”