Rabbit Anti-Human DTNB (C-terminal) Polyclonal antibody

Introduction: This study aims to compare the antioxidant abilities of cervical squamous carcinoma cells and cervical adenocarcinoma cells and to study the related mechanisms. Material and method: Cervical squamous carcinoma and adenocarcinoma cells were treated with H2O2. Cell proliferation was determined with the MTT assay. The reactive oxygen species (ROS) level was detected by the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) method. The 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) method was performed to measure intracellular concentrations of reduced glutathione (GSH) and oxidized glutathione (GSSG). The nitrite formation method, the molybdate colorimetric method, and the DTNB colorimetric method were used to determine activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), respectively. Results: Compared with untreated control cells, cell proliferation of cervical squamous carcinoma cells and cervical adenocarcinoma cells was significantly inhibited by H2O2 treatment (p < 0.05). Reactive oxygen species levels and GSSG levels were significantly increased (p < 0.01), whereas GSH levels were significantly decreased (p < 0.05 or 0.01) in both cells after H2O2 treatment. Thus the ratio of GSH/GSSG was significantly decreased by H2O2 treatment in both cells (p < 0.01). In addition, H2O2 treatment significantly increased activities of SOD, CAT, and GPx in both cells (p < 0.05 or 0.01). Furthermore, the above-mentioned changes induced by H2O2 treatment were more dramatic in cervical squamous carcinoma cells. Conclusions: The antioxidant ability of cervical squamous carcinoma cells is lower than that of cervical adenocarcinoma cells, which may be related to the increased ROS levels in cervical squamous carcinoma cells induced by H2O2 treatments.

This paper describes the cloning, purification and characterization of thioredoxin (TrxA) and thioredoxin reductase (TrxR) from bacterial strain Streptomyces coelicolor. The genes of S. coelicolor encoding TrxA and TrxR were amplified by polymerase chain reaction, inserted into pET expression vector and used to overexpress these proteins in Escherichia coli. TrxA and TrxR were produced as the hexahistidine fusion proteins and were recovered from the cytoplasm as the soluble proteins. The activity of the purified recombinant proteins was demonstrated. The activity of TrxA was shown by efficient reduction of insulin and activity of NADPH-dependent TrxR was revealed by catalyses of 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB) reduction reaction. The reduction reaction was fully dependent upon the presence of TrxA as intermediate electron carrier with the pH optimum 7.5 and the temperature optimum 29 degrees C. K value of TrxR for TrxA was 0.217 +/- 0.02 mu M.