The TDO Fluorogenic Inhibitor Screening Assay Kit is designed to measure enzyme inhibition of tryptophan 2,3-dioxygenase (TDO). The TDO Fluorogenic Inhibitor Screening Assay Kit is simple to use and detects fluorescence at long wavelengths, which minimizes potential errors due to compound interference. In the assay, the inhibitor and enzyme are added to a sample containing L-Trp substrate. After a 1 hour incubation at room temperature, the fluorescence solution is added and incubated at 37°C for four hours. Activity is measured by reading sample fluorescence at λ=510 nm following excitation of the reaction product at λ=400 nm.
The kit comes in a convenient format, with enough reaction solution and enzyme to perform a total of 400 reactions.
Format
Catalog Number
Component
Amount
Storage
71195
TDO His-Tag*
100 μg
-80°C
(Avoid freeze/thaw cycles!)
73010
TDO Fluorogenic Reaction Solution
3 x 10 ml
-80°C
73006
TDO Buffer
3 ml
-80°C
Fluorescence Solution
4 x 1 ml
-80°C
79961
Black 384 Wells Assay-Plate
1
Plate sealing film
1
*The concentration of TDO is lot-specific and will be indicated on the tube containing the enzyme.
UniProt #
P48775
Background
L-tryptophan (L-Trp) is an essential amino acid necessary for protein
synthesis in mammalian cells and the L-Trp to kynurenine (Kyn) pathway is firmly established as
a key regulator of innate and adaptive immunity. Catabolism of L-Trp to Kyn maintains an
immunosuppressive microenvironment by starving immune cells of L-Trp and releasing
degradation products of L-Trp that have immunosuppressive functions. Tryptophan 2,3
dioxygenase (TDO), a rate limiting enzymes in this pathway, is upregulated in many tumors,
providing cancer cells with an avenue for immune evasion.
References
Seegers, N., et al. J. Biomol. Screen. 2014. 19(9):1266-74.
Storage/Stability
Stable at least 6 months from date of receipt, when stored as directed. Kit components require different storage conditions. Be sure to store each component at the proper temperature upon arrival.
Instructions for Use
See assay kit data sheet for detailed protocol
Applications
Useful for the study of TDO enzymology, inhibitor screening, and selectivity profiling.
Shipping Temperature
-80°C (dry ice)
Contraindications
DMSO >0.5%, strong acids or bases, ionic detergents, high salt.
Warning: the Fluorescence Solution contains a component that is known to be a skin and eye
irritant. Use caution and appropriate personal protective equipment when handling this
component.
Warnings
Avoid freeze/thaw cycles.
Disclaimers and Limitations
BPS Bioscience assay kits are validated using the listed components according to our specific protocol. Any deviations to kit components or protocols, such as using different proteins, cell/tissue lysates, or buffers (including using the same component from other commercial sources) will void any warranties on the performance of the assay kit and is not recommended.
End-users should immediately report any issues to [email protected] upon receipt of the kit, such as missing components, damaged vials, no dry ice, etc.