Journal
BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS
Volume 1794, Issue 10, Pages 1505-1509Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.bbapap.2009.06.013
Keywords
Calpain; Protease; Calcium; Peptide substrate; FRET; Peptidase
Categories
Funding
- R.S. McLaughlin Fellowship
- Natural Sciences and Engineering Research Council (NSERC) studentship from the Government of Canada
- Canada Research Chair in Protein Engineering
- Canadian Institutes for Health Research
Ask authors/readers for more resources
Calpains are intracellular proteases that selectively cleave proteins in response to calcium signals. Although calpains cut many different sequences, residue preferences within peptide substrates were recently determined and incorporated into a superior FRET (fluorescence resonance energy transfer)-based substrate (PLFAER). Here we show PLFAER is cleaved by calpain at the intended F-A scissile bond. Sequential replacement of individual residues by alanine reduced activity except with PLFAAR, which is cleaved 2.3 times faster than PLFAER. The rates of hydrolysis of the alanine-substituted substrates were used to compare substrate preferences of calpain, papain and cathepsins B and L The preferences of the two major isoforms, calpains 1 and 2, were virtually indistinguishable and were very similar to those of the calpain I protease core and papain. However, the activity profiles with the FRET substrate series were significantly different for the cathepsins, particularly cathepsin B. (C) 2009 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available