A potent reporter applicable to the monitoring of caspase-3-dependent proteolytic cleavage

J Biotechnol. 2008 Nov 6;138(1-2):17-23. doi: 10.1016/j.jbiotec.2008.07.1999. Epub 2008 Aug 15.

Abstract

In this study, we developed a chimeric caspase-3 substrate (GST:DEVD:EGFP) comprised of glutathione-S transferase (GST) and enhanced green fluorescent protein (EGFP) with a specialized linker peptide harboring the caspase-3 cleavage sequence, DEVD. Using this reporter, we assessed the proteolytic cleavage of the artificial caspase-3 substrate for caspase-3. The common feature of this approach is that the presence of the DEVD sequence between GST and EGFP allows for caspase-3-dependent cleavage after the Asp (D) residue, resulting in the elimination of EGFP from the GST:DEVD:EGFP reporter. To the best of our knowledge, this study reports the first application employing a chimeric protein substrate, with the similar accuracy level compared to the conventional methods such as fluorometric assays. As a result, using this GST:DEVD:EGFP reporter, caspase-3 activation based on proteolytic properties could be monitored via a variety of bioanalytical techniques such as immunoblot analysis, glutathione-agarose bead assay, and on-chip visualization, providing both technical and economical advantages over the extensively utilized fluorogenic peptide assay. Our results convincingly showed that this versatile reporter (GST:DEVD:EGFP) constitutes a useful system for the monitoring of caspase-3 activation, potentially enabling the monitoring of the proteolytic activities of different intra-cellular proteases via the substitution of the cleavage sequence within the same schematic construct.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Caspase 3 / genetics*
  • Caspase 3 / metabolism*
  • Cell Line, Tumor
  • Colonic Neoplasms / enzymology*
  • Colonic Neoplasms / genetics
  • Enzyme Activation
  • Genes, Reporter / genetics*
  • Green Fluorescent Proteins / genetics
  • Humans
  • Microscopy, Fluorescence / methods*
  • Signal Transduction / genetics*

Substances

  • Green Fluorescent Proteins
  • Caspase 3