1. Metabolic Enzyme/Protease
  2. E1/E2/E3 Enzyme


Cat. No.: HY-13296 Purity: >98.0%
Handling Instructions

PYR-41 is a specific and cell permeable inhibitor of ubiquitin-activating enzyme E1 with an IC50 of < 10 μM, with no or little activity at E2.

For research use only. We do not sell to patients.
PYR-41 Chemical Structure

PYR-41 Chemical Structure

CAS No. : 418805-02-4

Size Price Stock Quantity
Free Sample (0.5-1 mg)   Apply now  
10 mM * 1 mL in DMSO USD 79 In-stock
5 mg USD 72 In-stock
10 mg USD 120 In-stock
50 mg USD 456 In-stock
100 mg USD 864 In-stock
200 mg   Get quote  
500 mg   Get quote  

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  • Biological Activity

  • Protocol

  • Technical Information

  • Purity & Documentation

  • References


PYR-41 is a specific and cell permeable inhibitor of ubiquitin-activating enzyme E1 with an IC50 of < 10 μM, with no or little activity at E2.

IC50 & Target

IC50: < 10 μM (E1)

In Vitro

PYR-41 increases total sumoylation in cells in addition to blocking ubiquitylation. PYR-41 attenuates cytokine-mediated nuclear factor-κB activation. PYR-41 also prevents the downstream ubiquitylation and proteasomal degradation of IκBα. Furthermore, PYR-41 inhibits degradation of p53 and activates the transcriptional activity of this tumor suppressor[1]. PYR-41 (50 μM) promotes accumulation of ubiquitinated proteins. PYR-41 causes a concentration-dependent (10-50 μM) decline in DUB activity in Z138 cells after 4 h. PYR-41 potently inhibits USP5 DUB activity, even at the lowest concentration (10 μM). PYR-41 potently (10-50 μM) inhibits the activity of various DUBs, determined to represent USP9x, USP5, USP14, UCH37 and UCH-L3. Co-treatment of Z138 cells with DTT and PYR-41 completely abolishes the accumulation of ubiquitinated proteins[2].

Preparing Stock Solutions
Concentration Volume Mass 1 mg 5 mg 10 mg
1 mM 2.6932 mL 13.4662 mL 26.9324 mL
5 mM 0.5386 mL 2.6932 mL 5.3865 mL
10 mM 0.2693 mL 1.3466 mL 2.6932 mL
Please refer to the solubility information to select the appropriate solvent.
Kinase Assay

Rabbit or mouse E1 (apper 250 ng) is incubated with 32P-ubiquitin in 1× reaction buffer [50 mM Tris (pH 7.4), 0.2 mM ATP, 0.5 mM MgCl2] at room temperature for 15 min. In some experiments, the His-tagged mouse E1 is bound to TALON cobalt affinity resin before carrying out incubations and reactions. Mouse E1 and 32P-ubiquitin are added to the beads in 1× reaction buffer and incubated as for E1 reactions. Samples are heated in nonreducing SDS-PAGE sample buffer and resolved by SDS-PAGE. Thioesters with ubiquitin are visualized by Storm PhosphoImager. MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Molecular Weight








Powder -20°C 3 years
  4°C 2 years
In solvent -80°C 6 months
  -20°C 1 month

Room temperature in continental US; may vary elsewhere

Solvent & Solubility

DMSO: ≥ 46 mg/mL

* "<1 mg/mL" means slightly soluble or insoluble. "≥" means soluble, but saturation unknown.

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