The transformation product of lactacystin clasto-lactacystin β-lactone (also known as omuralide) covalently modifies the amino-terminal threonine of specific catalytic subunits of the proteasome, a discovery that helped to establish the proteasome as a mechanistically novel class of protease: an amino-terminal threonine protease. The molecule is commonly used in biochemistry and cell biology laboratories as a selective inhibitor of the proteasome. The first total synthesis of lactacystin was developed in 1992 by Corey and Reichard, and a number of other syntheses of this molecule have also been published.
Lactacystin transforms into clasto-lactacystin β-lactone (also known as omuralide), which covalently modifies the amino-terminal threonine of specific catalytic subunits of the proteasome. This finding established the proteasome as a novel class of protease: an amino-terminal threonine protease. The molecule is widely used in biochemistry and cell biology laboratories for selective inhibition of the proteasome. Corey and Reichard developed the first total synthesis of lactacystin in 1992, and numerous other syntheses have been published.