1. Metabolic Enzyme/Protease Apoptosis
  2. E1/E2/E3 Enzyme Apoptosis
  3. PYR-41


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

PYR-41 is a selective and cell permeable inhibitor of ubiquitin-activating enzyme E1 with an IC50 of < 10 μM, with little activity at E2 and E3.

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
10 mM * 1 mL in DMSO USD 73 In-stock
Solid + Solvent
10 mM * 1 mL
ready for reconstitution
USD 73 In-stock
5 mg USD 66 In-stock
10 mg USD 99 In-stock
50 mg USD 396 In-stock
100 mg USD 616 In-stock
200 mg   Get quote  
500 mg   Get quote  

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This product is a controlled substance and not for sale in your territory.

Customer Review

Based on 11 publication(s) in Google Scholar

Top Publications Citing Use of Products

    PYR-41 purchased from MCE. Usage Cited in: Int Immunopharmacol. 2020 Oct;87:106763.  [Abstract]

    293 T cells are pretreated with DMSO or PYR41 for 3 h, and then PYR41 inhibitor is added followed by stimulation with IFNα and VSV. After 24 h, VSVG protein expression level is determined by Western blotting analyses.

    PYR-41 purchased from MCE. Usage Cited in: Mol Cell Biol. 2018 Jul 16;38(15). pii: e00024-18.  [Abstract]

    Western blotting assays demonstrate that treatment of 20 μM PYR-41 or 20 μM PYZD-4409 inhibits ubiquitination and CD133 secretion. Hsp90 and β-actin are used as loading controls.
    • Biological Activity

    • Protocol

    • Purity & Documentation

    • References

    • Customer Review


    PYR-41 is a selective and cell permeable inhibitor of ubiquitin-activating enzyme E1 with an IC50 of < 10 μM, with little activity at E2 and E3.

    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].

    MCE has not independently confirmed the accuracy of these methods. They are for reference only.

    Molecular Weight






    CAS No.



    Room temperature in continental US; may vary elsewhere.

    Powder -20°C 3 years
    4°C 2 years
    In solvent -80°C 6 months
    -20°C 1 month
    Solvent & Solubility
    In Vitro: 

    DMSO : ≥ 46 mg/mL (123.89 mM)

    *"≥" means soluble, but saturation unknown.

    Stock Solutions
    Concentration Solvent 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.
    In Vivo:
    • 1.

      Add each solvent one by one:  10% DMSO    40% PEG300    5% Tween-80    45% saline

      Solubility: ≥ 2.5 mg/mL (6.73 mM); Clear solution

    *All of the co-solvents are available by MCE.
    Purity & Documentation

    Purity: ≥98.0%

    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.

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    Help & FAQs
    • Do most proteins show cross-species activity?

      Species cross-reactivity must be investigated individually for each product. Many human cytokines will produce a nice response in mouse cell lines, and many mouse proteins will show activity on human cells. Other proteins may have a lower specific activity when used in the opposite species.

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    This equation is commonly abbreviated as: C1V1 = C2V2

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    × = ×
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