Molecular Weight(MW): 335.4
Tubastatin A is a potent and selective HDAC6 inhibitor with IC50 of 15 nM in a cell-free assay. It is selective against all the other isozymes (1000-fold) except HDAC8 (57-fold).
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|Description||Tubastatin A is a potent and selective HDAC6 inhibitor with IC50 of 15 nM in a cell-free assay. It is selective against all the other isozymes (1000-fold) except HDAC8 (57-fold).|
Tubastatin A is selective at all isozymes except HDAC8 and maintains over 1000-fold selectivity against all isoforms excluding HDAC8, where it has approximately 57-fold selectivity. Tubastatin A preferentially induces α-tubulin hyperacetylation at 2.5 μM. Slight induction of histone hyperacetylation is seen for Tubastatin A at 10 μM. Tubastatin A displays dose-dependent protection against homocysteic acid-induced neuronal cell death starting at 5 μM with near complete protection at 10 μM.  Tubastatin A (10 μM) induces an increase in acetylated-α-tubulin levels and the restoration of primary cilia expression in the cholangiocarcinoma cell lines (18-fold); and the restoration of primary cilia correlated with downregulated Hedgehog (Hh) and MAPK signaling pathways, as well as decreased cell proliferation rates (in average by 50%) and invasion (by 40%).  Tubastatin A shows significant inhibition of TNF-α and IL-6 in LPS stimulated human THP-1 macrophages with an IC50 of 272 nM and 712 nM. Tubastatin A inhibits nitric oxide (NO) secretion in murine Raw 264.7 macrophages dose depenndently with an IC50 of 4.2 μM. 
|In vivo||Tubastatin A reduces the growth of cholangiocarcinoma in vivo. Tubastatin A (10 mg/kg) induces a 6-fold lower mean tumor weights in syngeneic rat orthotopic model of cholangiocarcinoma, and reduction of the ratios of tumor weight to liver weight and body weight (5- and 5.6-fold, respectively), as well as a greater frequency of ciliated cholangiocytes compared with controls (29% vs 1.4%). Tubastatin A significantly decreases the amount of PCNA-positive cells in the treated tumors compared with vehicle controls (34% vs 65%).  Tubastat A shows significant inhibition of paw volume at 30 mg/kg i.p. in a Freund's complete adjuvant (FCA) induced animal model of inflammation. Tubastat A (30 mg/kg i.p.) significant attenuates clinical scores (~ 70%), and IL-6 expression in paw tissues of collagen induced arthritis DBA1 mouse. |
HDAC enzymatic assays:Tubastatin A is dissolved and diluted in assay buffer (50 mM HEPES, pH 7.4, 100 mM KCl, 0.001% Tween-20, 0.05% BSA, and 20 μM tris(2-carboxyethyl)phosphine) to 6-fold of the final concentration. HDAC enzymes are diluted to 1.5-fold of the final concentration in assay buffer and pre-incubated with Tubastatin A for 10 minutes before the addition of the substrate. The amount of FTS (HDAC1, HDAC2, HDAC3, and HDAC6) or MAZ-1675 (HDAC4, HDAC5, HDAC7, HDAC8, and HDAC9) used for each enzyme is equal to the Michaelis constant (Km), as determined by a titration curve. FTS or MAZ-1675 is diluted in assay buffer to 6-fold the final concentration with 0.3 μM sequencing grade trypsin. The substrate/trypsin mix is added to the enzyme/compound mix and the plate is shaken for 60 seconds and then placed into a SpectraMax M5 microtiter plate reader. The enzymatic reaction is monitored for release of 7-amino-4-methoxy-coumarin over 30 minutes, after deacetylation of the lysine side chain in the peptide substrate, and the linear rate of the reaction is calculated.
|In vitro||DMSO||67 mg/mL (199.76 mM)|
|In vivo||Add solvents to the product individually and in order(Data is from Selleck tests instead of citations):
4% DMSO+30% PEG 300+ddH2O
For best results, use promptly after mixing.
* Please note that Selleck tests the solubility of all compounds in-house, and the actual solubility may differ slightly from published values. This is normal and is due to slight batch-to-batch variations.
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Frequently Asked Questions
We are planning to order some tubastatin A but I found out there are two versions of it. One has HCl and one does not. Which one do you recommend for live cell use? Will the HCl containing version significantly change the pH?
S8049 and S2627 have same molecular structure. The only difference is S2627 containing HCl and has higher solubility in DMSO (74 mg/mL vs. S8049 9 mg/mL). Since they are the same molecule, the biological function should be similar. I would recommend to use S2627 for cell culture study.
What’s the vehicle do you recommend to dissolve the compound for in vivo experiments?
S8049 Tubastatin A can be dissolved in 2% DMSO/30% PEG 300/PBS at 2.5 mg/mL as a clear solution, and it is also a clear solution in 2% DMSO/ corn oil at 2.5 mg/mL. The drug in 2% DMSO/0.5% Tween 80/PBS is a homogeneous suspension at 2.5 mg/mL at first. After stay for a while, the precipitation goes out at the bottom of the tube.