NQO1 Human, Active
Description
Detoxification and Redox Regulation
-
Quinone Detoxification: Reduces reactive quinones (e.g., menadione, anthracyclines) to non-redox-active hydroquinones, preventing oxidative stress .
-
Endogenous Quinone Metabolism:
Stabilization of Tumor Suppressor Proteins
NQO1 binds and stabilizes proteins like p53 and HIF-1α, preventing their proteasomal degradation .
Bioactivation of Anticancer Prodrugs
NQO1 selectively activates quinone-based prodrugs in tumors with elevated expression (up to 200-fold vs. normal tissues) .
Cancer-Selective Expression
NQO1 overexpression is observed in breast, colon, lung, pancreatic, and hepatocellular carcinomas, correlating with poor prognosis .
| Cancer Type | NQO1 Overexpression | Associated Pathway | Sources |
|---|---|---|---|
| Colorectal | ↑ HIF-1α → ↑ VEGF | Angiogenesis, hypoxia adaptation | |
| Hepatocellular | ↑ TAM polarization | Immunosuppressive microenvironment |
Targeted Therapies
Diagnostic and Prognostic Biomarkers
-
Hepatocellular carcinoma (HCC): High NQO1 expression correlates with M2 macrophage polarization and poor survival .
-
Nomogram Models: Integration of NQO1-related genes (NRGs) with clinical factors (e.g., pTNM stage) improves survival prediction (AUC >0.7) .
Theranostic Applications
Product Specs
Recombinant human NQO1, expressed in E. coli, is a single, non-glycosylated polypeptide chain consisting of 294 amino acids (residues 1-274) with a molecular weight of 33.0 kDa. It includes a 20 amino acid His tag at the N-terminus and is purified using proprietary chromatographic techniques.
The NQO1 solution is provided at a concentration of 1 mg/ml in a buffer consisting of 20mM Tris-HCl (pH 8.0), 1mM DTT, and 10% glycerol.
The specific activity of the enzyme is greater than 1,000 pmol/min/ug, measured as the conversion of resazurin to resorufin at a rate exceeding 1 pmol per minute per microgram of protein at pH 7.5 and 25°C.
MGSSHHHHHH SSGLVPRGSH MVGRRALIVL AHSERTSFNY AMKEAAAAAL KKKGWEVVES
DLYAMNFNPI ISRKDITGKL KDPANFQYPA ESVLAYKEGH LSPDIVAEQK KLEAADLVIF
QFPLQWFGVP AILKGWFERV FIGEFAYTYA AMYDKGPFRS KKAVLSITTG GSGSMYSLQG
IHGDMNVILW PIQSGILHFC GFQVLEPQLT YSIGHTPADA RIQILEGWKK RLENIWDETP
LYFAPSSLFD LNFQAGFLMK KEVQDEEKNK KFGLSVGHHL GKSIPTDNQI KARK
Product Science Overview
NQO1 is a cytoplasmic, homodimeric protein, meaning it forms a complex of two identical subunits. Each subunit binds one molecule of flavin adenine dinucleotide (FAD), which is essential for its enzymatic activity . The primary function of NQO1 is to catalyze the two-electron reduction of quinones to hydroquinones using NADH or NADPH as reducing cofactors . This reaction is vital because it prevents the formation of semiquinone radicals and reactive oxygen species (ROS), which can cause cellular damage .
NQO1 is widely expressed in various tissues, including epithelial and endothelial tissues, where it plays a significant role in detoxifying quinones and protecting cells from oxidative stress . The enzyme’s activity is crucial for maintaining cellular redox balance and preventing oxidative damage to DNA, proteins, and lipids .
NQO1 has been extensively studied for its role in cancer biology. It is known to be overexpressed in several types of tumors, including breast, lung, pancreatic, and colon cancers . The overexpression of NQO1 in cancer cells is thought to provide a survival advantage by enhancing the detoxification of quinones and reducing oxidative stress . Additionally, NQO1 stabilizes the tumor suppressor protein p53, protecting it from degradation and thereby contributing to the regulation of cell cycle and apoptosis .
Given its role in detoxification and cancer biology, NQO1 has been targeted for therapeutic interventions. Compounds such as mitomycin C, β-lapachone, and other quinone derivatives are known to exploit NQO1’s enzymatic activity to induce cytotoxicity selectively in cancer cells . These compounds undergo bioactivation by NQO1, leading to the generation of cytotoxic species that can kill cancer cells while sparing normal cells .
Recombinant NQO1, expressed in systems such as Escherichia coli, is used in research to study its structure, function, and interactions with various substrates and inhibitors . The availability of human recombinant NQO1 allows for detailed biochemical and biophysical analyses, facilitating the development of NQO1-targeted therapies and diagnostic tools .
