Related Experiment Videos
A combinatorial approach for determining protease specificities: application to interleukin-1beta converting enzyme
T A Rano1, T Timkey, E P Peterson
1Department of Molecular Design and Diversity, Merck Research Laboratories, R123-232, PO Box 2000, Rahway, New Jersey 07065, USA.
Chemistry & Biology
|February 1, 1997
Summary
A new method reveals the optimal recognition sequence for Interleukin-1beta converting enzyme (ICE/caspase-1) is WEHD, not YVAD. This finding led to a potent inhibitor, advancing protease specificity research.
Area of Science:
- Biochemistry
- Enzymology
- Molecular Biology
Background:
- Interleukin-1beta converting enzyme (ICE/caspase-1) is a key protease in interleukin-1beta (IL-1beta) production.
- ICE/caspase-1 is the first identified member of a cysteine protease family involved in inflammation and apoptosis.
Purpose of the Study:
- To determine the precise amino-acid preferences and specificity of ICE/caspase-1.
- To develop a rapid and accurate method for assessing protease specificity.
Main Methods:
- Utilized a novel positional-scanning substrate library to map protease specificity.
- Synthesized an aldehyde inhibitor based on the determined optimal sequence.
- Employed X-ray crystallography to elucidate the structural basis of inhibition.
Main Results:
- Identified the optimal tetrapeptide recognition sequence for ICE/caspase-1 as WEHD.
- Demonstrated that the previously believed sequence YVAD was incorrect.
- Synthesized a highly potent aldehyde inhibitor, Ac-WEHD-CHO, with a Ki of 56 pM.
Conclusions:
- Positional-scanning libraries are powerful tools for rapid and accurate protease specificity assessment.
- The WEHD sequence suggests ICE/caspase-1 may have additional endogenous substrates beyond IL-1beta.
- Findings support the role of ICE/caspase-1 in apoptosis and IL-1alpha production.