442633-00-3

Basic information

• Product Name: 2-Fluoro-N-[2-(2-methyl-1H-indol-3-yl)ethyl]benzamide
• Synonyms: 2-Fluoro-N-[2-(2-methyl-1H-indol-3-yl)ethyl]benzamide;CK 666;CK-0944666;Arp2/3 Complex Inhibitor I, CK-666
• CAS NO: 442633-00-3
• Molecular Formula: C₁₈H₁₇FN₂O
• Molecular Weight: 296
• Mol File: 442633-00-3.mol
• Article Data: 1

Chemical Properties

• Boiling Point: 528.2±50.0 °C(Predicted)
• Appearance: white to tan/
• Density: 1.235±0.06 g/cm3(Predicted)
• Storage Temp.: Store at -20°C
• Solubility: DMSO: ≥25mg/mL
• PKA: 13.86±0.46(Predicted)
• Stability: Stable for 1 year from date of purchase as supplied. Solutions in DMSO or ethanol may be stored at -20°C for up to 3 months.
• CAS DataBase Reference: 2-Fluoro-N-[2-(2-methyl-1H-indol-3-yl)ethyl]benzamide(CAS DataBase Reference)
• NIST Chemistry Reference: 2-Fluoro-N-[2-(2-methyl-1H-indol-3-yl)ethyl]benzamide(442633-00-3)
• EPA Substance Registry System: 2-Fluoro-N-[2-(2-methyl-1H-indol-3-yl)ethyl]benzamide(442633-00-3)

Safety Data

• Hazard Codes: Xi
• Statements: 36
• Safety Statements: 26
• WGK Germany: 3
• Hazardous Substances Data: 442633-00-3(Hazardous Substances Data)

Usage

Description

CK-666 (442633-00-3) is a potent, selective and reversible inhibitor of ARP2/3 complex (actin related proteins 2 and 3) with an IC50?= 4 μM for human ARP2/3.1?Blocks actin nucleation and radically alters lamellipodial actin architecture, suspended cell shape and the cell spreading process.2 CK-666 attenuates BBB dysfunction induced by methamphetamine.3?It is an important new tool for studying actin assembly and the diverse range of actin-related processes in normal4 and pathophysiology5.

Uses

CK-666 may be used to study Arp2/3-mediated structural changes in cells.

General Description

A cell-permeable indolyl-fluorobenzamide compound that selectively inhibits actin assembly mediated by actin-related protein Arp2/3 complex of human, bovine, fission yeast S. pombe, and budding yeast S. cerevisiae origin (IC50 = 4, 17, 5, and 12 μM, respectively), without affecting S. pombe formin domain Cdc12(FH2)-mediated or the spontaneous actin polymerization. Shown to inhibit the actin filament "comet tails" formation around intracellular Listeria in infected SKOV3 cells (IC50 = 7 μM) in a reversible manner. Structrual studies indicate that CK-666 targets a pocket formed between subdomain 4 of Arp2 and subdomain 1 of Arp3, preventing Arp2/3 from shifting into an active conformation upon N-WASP-VCA binding. CK-666 and CK-869 (Cat. No. 182516) exhibit different modes of binding, resulting in their different yeast cross-reactivities. CK-689 (Cat. No. 182517) can serve as a negative control.

Biochem/physiol Actions

CK-666 binds to Arp2/3 complex, stabilizes the inactive state of the complex and prevents its movement into active conformation.

References

1) Nolan et al. (2009), Characterization of two classes of small molecule inhibitors of Arp2/3 complex; Nature, 460 1031 2) Henson et al. (2015), Arp2/3 complex inhibition radically alters lamellipodial actin architecture, suspended cell shape, and the cell spreading process; Mol. Biol. Cell, 26 887 3) Park et al. (2013), Methamphetamine-induced occluding endocytosis is mediated by the Arp2/3 complex-regulated actin rearrangement; J. Biol. Chem., 288 33324 4) Sun et al. (2013), Actin nucleator Arp2/3 complex is essential for mouse preimplantation embryo development; Reprod. Fertil. Dev., 25 617 5) Efremov et al. (2015), Distinct impact of targeted actin cytoskeleton reorganization on mechanical properties of normal and malignant cells; Biochim. Biophys. Acta, 1853 (11PtB) 3117

Upstream product

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• 5416-80-8 2-methyl-1H-indole-3-carbaldehyde 
• 95-20-5 2-methyl-1H-indole 

Relevant articles and documents

Structural Characterization and Computer-Aided Optimization of a Small-Molecule Inhibitor of the Arp2/3 Complex, a Key Regulator of the Actin Cytoskeleton

CK-666 (1) is a recently discovered small-molecule inhibitor of the actin-related protein 2/3 (Arp2/3) complex, a key actin cytoskeleton regulator with roles in bacterial pathogenesis and cancer cell motility. Although 1 is commercially available, the crystal structure of Arp2/3 complex with 1 bound has not been reported, making its mechanism of action uncertain. Furthermore, its relatively low potency increases its potential for off-target effects invivo, complicating interpretation of its influence in cell biological studies and precluding its clinical use. Herein we report the crystal structure of 1 bound to Arp2/3 complex, which reveals that 1 binds between the Arp2 and Arp3 subunits to stabilize the inactive conformation of the complex. Based on the crystal structure, we used computational docking and free-energy perturbation calculations of monosubstituted derivatives of 1 to guide optimization efforts. Biochemical assays of ten newly synthesized compounds led to the identification of compound 2, which exhibits a threefold increase in inhibitory activity invitro relative to 1. In addition, our computational analyses unveiled a surface groove at the interface of the Arp2 and Arp3 subunits that can be exploited for additional structure-based optimization.