PMID: 16511067 , Related PDB ids: 1RWK, 1RWM, 1RWN, 1RWO, 1RWP, R1RWKSF, R1RWMSF, R1RWNSF, R1RWOSF, R1RWPSF

Authors:

O'Brien T, Fahr BT, Sopko MM, Lam JW, Waal ND, Raimundo BC, Purkey HE, Pham P, Romanowski MJ

Title:

Structural analysis of caspase-1 inhibitors derived from Tethering.

Journal:

Acta Crystallogr Sect F Struct Biol Cryst Commun. 2005 May 1;61(Pt, 5):451-8. Epub 2005 Apr 9.

Abstract:

Caspase-1 is a key endopeptidase responsible for the post-translational processing of the IL-1beta and IL-18 cytokines and small-molecule inhibitors that modulate the activity of this enzyme are predicted to be important therapeutic treatments for many inflammatory diseases. A fragment-assembly approach, accompanied by structural analysis, was employed to generate caspase-1 inhibitors. With the aid of Tethering with extenders (small molecules that bind to the active-site cysteine and contain a free thiol), two novel fragments that bound to the active site and made a disulfide bond with the extender were identified by mass spectrometry. Direct linking of each fragment to the extender generated submicromolar reversible inhibitors that significantly reduced secretion of IL-1beta but not IL-6 from human peripheral blood mononuclear cells. Thus, Tethering with extenders facilitated rapid identification and synthesis of caspase-1 inhibitors with cell-based activity and subsequent structural analyses provided insights into the enzyme's ability to accommodate different inhibitor-binding modes in the active site.