Electrochemical proteolytic beacon for detection of matrix metalloproteinase activities.
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.
Liu
Guodong
G
Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
Wang
Jun
J
Wunschel
David S
DS
Lin
Yuehe
Y
D004563:Electrochemistry; D005296:Ferrous Compounds / Q000737:chemistry*; D020783:Matrix Metalloproteinase 7 / Q000737:chemistry* / Q000378:metabolism*; D000075163:Metallocenes; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D017433:Protein Structure, Secondary
D005296:Ferrous Compounds; D000075163:Metallocenes; D009842:Oligopeptides; D020783:Matrix Metalloproteinase 7; C004998:ferrocene