Analyte: Thioredoxin
Specimen Type: Serum
Optimum Volume: 0.5 mL
Reporting Units: ng/mL
Method: ELISA
2-8°C 6 days
-20°C N.A.*
-70°C N.A.*

Biological or Clinical Significance:

Thioredoxins (Trx) are small, multi-functional proteins with oxido-reductase activity and are ubiquitous in essentially all living cells. Trx contains a redox-active disulfide/dithiol group within the conserved Cys-Gly-Pro-Cys active site. The two cysteine residues in the conserved active centers can be oxidized to form intramolecular disulfide bonds. Reduction of the active site disulfide in oxidized Trx is catalyzed by Trx reductase with NADPH as the electron donor. The reduced Trx is a hydrogen donor for ribonucleotide reductase, the essential enzyme for DNA synthesis, and a potent general protein disulfide reductase with numerous functions in growth and redox regulations. Trx is also capable of removing H2O2, particularly when it is coupled with either methionine sulfoxide reducatase or several isoforms of peroxiredoxins.

Thioredoxin-1 (Trx1) is a 12 kDa protein containing the active cysteine residues 32 and 35. Trx1 found primarily in the cytosol and occasionally in the nucleus, plays critical roles in regulating protein thiol homeostasis and redox signaling both inside and outside the cellular environment. Trx1 regulates a wide range of cellular functions, including cell growth, proliferation, and apoptosis. Its dysfunction is associated with a variety of diseases in which redox imbalance has been implicated, including cancer, human immunodeficiency virus infection, neurodegenerative diseases, and cardiovascular diseases. Trx1’s disulfide reduction function is widely recognized, and to a lesser degree it has been shown to modulate additional redox-dependent posttranslational modifications (PTMs), including transnitrosylation and denitrosylation of specific proteins.

Clinical interventions that target Trx1 for the modulation of protein disulfide reduction, nitrosylation, or denitrosylation may provide the specificities that are required for the management of diseases related to oxidative and nitrosative  mbalance and the design of personalized medicines.

Principle of Test Method:

The thioredoxin assay is sandwich Enzyme-Linked Immunosorbent Assay (ELISA).

*Please contact nexelis for stability information.


  1. Sumida Y, Nakashima T, Yoh T, Furutani M, Hirohama A, Kakisaka Y, Nakajima Y, Ishikawa H, Mistuyoshi H, Okanoue T, Kashima K, Nakamura H, Yodoi J. Serum thioredoxin levels as a predictor of steatohepatitis in patients with nonalcoholic fatty liver disease. Journal of Hepatology 2003;38: 32-28.