A new fluorescence turn-on assay for trypsin and inhibitor screening based on graphene oxide

ACS Appl Mater Interfaces. 2011 Apr;3(4):1175-9. doi: 10.1021/am2000104. Epub 2011 Mar 21.

Abstract

In this paper, we describe a new continuous fluorescence turn-on method for trypsin assay and inhibitor screening in situ. This assay is designed based on the following assumptions: (1) It is expected that the fluorescein-labeled peptide composed of six arginine residues (Arg(6)-FAM) with positive charges will interact with the negatively charged edge of water-soluble graphene oxide (GO) because of electrostatic interactions to form a GO/Arg(6)-FAM complex. As a result, the fluorescence of fluorescein will be quenched because of the energy transfer from fluorescein to GO. (2) Arg(6)-FAM can be hydrolyzed into small fragments in the presence of trypsin, and accordingly, the GO/Arg(6)-FAM complex will be dissociated, gradually leading to fluorescence recovery for the solution. In this way, the trypsin activity can be easily assayed with the ensemble of Arg(6)-FAM and GO. Additionally, the ensemble can be employed for screening of the inhibitors of trypsin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Drug Evaluation, Preclinical / methods*
  • Fluorescein / metabolism
  • Fluorescence*
  • Graphite / metabolism*
  • Oxides / metabolism*
  • Staining and Labeling / methods
  • Trypsin / metabolism*
  • Trypsin Inhibitors / isolation & purification*
  • Trypsin Inhibitors / pharmacology*

Substances

  • Oxides
  • Trypsin Inhibitors
  • Graphite
  • Trypsin
  • Fluorescein