HOIPIN-1 (JTP-0819958) is a selective linear ubiquitin chain assembly complex (LUBAC) inhibitor (antagonist) with IC50 >2.8 μM. HOIPIN-1 inhibits LUBAC-mediated NF-kB activation.

Physicochemical Properties

Molecular Formula	C17H13NAO4
Molecular Weight	304.28
PubChem CID	137628274
Appearance	White to light yellow solid powder
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	5
Heavy Atom Count	22
Complexity	407
Defined Atom Stereocenter Count	0
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	IKK-α IKK-β
ln Vitro	Petit-LUBAC was employed in the HTRF-based investigation of LUBAC-mediated ubiquitination. The inhibitory activity increases with the length of time HOIPIN-1 (0.9-120 μM) is preincubated in the reaction buffer. The IC50 values were 26 μM, 26 μM, 26 μM, and 3.926 μM at 1 h, 3 h, 6 h, and 24 h, respectively [1]. When LUBAC subunits are co-expressed in HEK293T cells, the quantity of intracellular linear polyubiquitin increases. In HEK293T cells that produce LUBAC, HOIPIN-1 (1-30 μM) dose-dependently decreases the amount of intracellular linear polyubiquitin. Generate [1]. In Hela cells, HOIPIN-1 (30-100 μM; 30-60 minutes) decreases the phosphorylation of IKKα/β, p105, and p65 and prevents NF-κB activation triggered by IL-1β [1]. In Hela cells, HOIPIN-1 (10-100 μM) dose-dependently suppresses the expression of NF-κB target genes, including TNF-α and ICAM1, that is activated by IL-1β [1]. Parts of the linear ubiquitin chain assembly complex (LUBAC) include HOIL-1L, HOIP, and SHARPIN. The linear polyubiquitination activity of HOIL-1L/HOIP complex, HOIL-1L/HOIP/SHARPIN complex, and HOIP/SHARPIN complex is inhibited by HOIPIN-1 with IC50 values of 4.4 μM, 3.5 μM, and 3.7 μM, respectively[2]. 72-hour HOIPIN-1 (1-100 μM) Based on ATP content, HOIPIN-1 (1-100 μM; 72 hours) does not demonstrate considerable cytotoxicity; however, it does show cytotoxicity in A549 cells, with an IC50 of > 100 μM in these cells[2].
References	[1]. High-Throughput Screening for Linear Ubiquitin Chain Assembly Complex (LUBAC) Selective Inhibitors Using Homogenous Time-Resolved Fluorescence (HTRF)-Based Assay System. SLAS Discov. 2018 Dec;23(10):1018-1029. [2]. Small-molecule inhibitors of linear ubiquitin chain assembly complex (LUBAC), HOIPINs, suppress NF-κB signaling. Biochem Biophys Res Commun. 2019 Feb 12;509(3):700-706.

Solubility Data

Solubility (In Vitro)

DMSO :~5 mg/mL (~16.43 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 0.5 mg/mL (1.64 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 5.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 0.5 mg/mL (1.64 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 5.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 0.5 mg/mL (1.64 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 5.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.2864 mL	16.4322 mL	32.8645 mL
	5 mM	0.6573 mL	3.2864 mL	6.5729 mL
	10 mM	0.3286 mL	1.6432 mL	3.2864 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.