Caspase-1 inhibitor - Ac-YVAD-cmk

Caspase-1 inhibitor

Inhibition of caspase signaling by Ac-YVAD-cmk

Ac-YVAD-cmk is a potent and irreversible inhibitor of the inflammatory caspase-1 [1]. Caspase-1, also known as IL-1 converting enzyme (ICE), is a cysteine protease that cleaves the precursors of the IL-1β and IL-18 pro-inflammatory cytokines, as well as the gasdermin D (GSDMD) pore-forming protein [2].

CASPASE-1 IN INFLAMMASOME RESPONSES:

Rapid responses to infections and tissue damages are largely mediated by the inflammasomes. The formation of these cytosolic signaling platforms occurs according to a consensual two-step model. The priming step (step 1) induces the transcription of pro-IL-1β. The activation step (step 2) triggers the multimerization of the activated inflammasome sensor with the ASC adaptor and pro-caspase-1. This assembly permits caspase-1 self-activation, which in turn induces the maturation of IL-1β and IL-18 cytokines. Activated caspase-1 also cleaves the N-terminal fragment of GSDMD, which accumulates to form pores at the cell membrane. These pores allow the unconventional secretion of IL-1β and IL-18, and in the absence of membrane repair, their accumulation leads to pyroptosis.

MODE OF ACTION OF Ac-YVAD-cmk:

Ac‑YVAD‑cmk is a tetrapeptide sequence based on the target sequence of caspase-1 in pro‑IL‑1β (YVHD) [1, 3]. This drug was described as blocking inflammatory cell death in experimental models [4]. Additional reports showed that Ac‑YVAD‑cmk effectively blocks inflammasome activation and that it displays anti-inflammatory, anti-apoptotic, and anti-pyroptotic effects [5, 6]. 

KEY FEATURES OF Ac‑YVAD‑cmk:

• Potent and irreversible inhibitor of caspase-1
• Weak inhibitor of caspase-4 and caspase-5 (human paralogs of caspase-1)
• Each lot is highly pure (≥97%) and functionally tested

Read our review oninflammasomes.

References

1. Garcia-Calvo M. et al., 1998. Inhibition of human caspases by peptide-based and macromolecular inhibitors. J Biol Chem. 273(49):32608-13. 2. Man SM & Kanneganti TD., 2016. Converging roles of caspases in inflammasome activation, cell death and innate immunity. Nat. Rev. Immunol. 16(1):7-21.3. Talanian, R.V., et al., 1997. Substrate specificities of caspase family proteases. J Biol Chem. 272(15):9677‑82.4. Schierle GS. et al., 1999. Caspase inhibition reduces apoptosis and increases survival of nigral transplants. Nat Med. 5(1):97-100.5. Van Opdenbosch N. et al., 2014. Activation of the NLRP1b inflammasome independently of ASC-mediated caspase-1 autoproteolysis and speck formation. Nat Commun. 5:3209.6. Zhang Y. et al, 2014. Involvement of inflammasome activation in lipopolysaccharide-induced mice depressive-like behaviors. CNS Neurosci Ther. 20(2):119-24.

Figures

Ac-YVAD-cmk inhibits NLRP3 inflammasome response in a dose-dependent manner.  THP1-Null2 cells were primed with LPS-EK (1 μg/ml) for 3h and then stimulated with MSU crystals (150 µg/ml) and increasing concentrations of Ac‑YVAD‑cmk. After 24h activation, the secretion of mature IL-1β in the culture supernatant was assessed using HEK-Blue™ IL-1β sensor cells and QUANTI‑Blue™ Solution detection reagent. The optical density (OD) was read at 655 nm.

Specifications

CAS number: 178603-78-6

Synonym: Acetyl-tyrosine-valine-alanine-aspartate‑chloromethyl ketone

Working concentration: 0.1–30 μg/ml for cell culture assays

Solubility: 50 mg/ml (92.4 mM) in DMSO

Formula: C₂₄H₃₃ClN₄O₈

Molecular weight: 541 g/mol

Quality control:

• Purity: ≥97% (UHPLC)
• The inhibitory activity of the product has been validated in inflammasome cellular assays using THP1-Null2 and HEK-Blue™ IL-1β cells.
• The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ TLR2 and HEK-Blue™ TLR4 cells.

Contents

• 5 mg Ac-YVAD-cmk (provided as a powder)

Ac-YVAD-cmk is shipped at room temperature.

Upon receipt, store at -20 °C.

Resuspended product is stable for at least 6 months when properly stored.

Avoid repeated freeze-thaw cycles.

Details

Chemical structure of Ac-YVAD-cmk: