Investigation of the effects of temperature and ions on the interaction between ECG and BSA by the fluorescence quenching method

The effects of temperature and common ions on binding (-)-epicatechin gallate (ECG) to bovine serum albumin (BSA) are investigated. The binding constants (Ka) between ECG and BSA are 1.20 Ч 106 (17°C), 1.38 Ч 106 (27°C), and 5.69 x 106 L mol-1 (37°C), and the number of binding sites (n) were 1.14, 1.15, and 1.26, respectively. These results showed that the increasing temperature improves the stability of the ECG-BSA system, which results in a higher binding constant and the number of binding sites of the ECG-BSA system. The presence of Co2+ and Zn2+ ions decreased the binding constants (Ka) and the number of binding sites (n) of ECG-BSA complex. However, the presence of Cu2+ and Ni2+ increased the affinity of ECG for BSA largely. The positive ΔH and positive ΔS indicated that hydrophobic forces might play a major role in the binding between ECG and BSA

Adsorption of Cr(VI) and Speciation of Cr(VI) and Cr(III) in Aqueous Solutions Using Chemically Modified Chitosan

A new type of grafting chitosan (CTS) was synthesized using 2-hydroxyethyl- trimethyl ammonium chloride (HGCTS). The adsorption of Cr(VI) on HGCTS was studied. The effect factors on adsorption and the adsorption mechanism were considered. The results indicated that the HGCTS could concentrate and separate Cr(VI) at pH 4.0; the adsorption equilibrium time was 80 min; the maximum adsorption capacity was 205 mg/g. The adsorption isotherm and kinetics were investigated, equilibrium data agreed very well with the Langmuir model and the pseudo second-order model could describe the adsorption process better than the pseudo first-order model. A novel method for speciation of Cr(VI) and Cr(III) in environmental water samples has been developed using HGCTS as adsorbent and FAAS as determination means. The detection limit of this method was 20 ng/L, the relatively standard deviation was 1.2% and the recovery was 99%~105%

Quantitative proteomics identification of phosphoglycerate mutase 1 as a novel therapeutic target in hepatocellular carcinoma

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with poor prognosis due to resistance to conventional chemotherapy and limited efficacy of radiotherapy. There is an urgent need to develop novel biomarkers for early diagnosis, as well as to identify new drug targets for therapeutic interventions. PATIENTS AND METHODS: 54 paired HCC samples and 21 normal liver tissues were obtained from West China Hospital of Sichuan University. Informed consent was obtained from all the patients or their relatives prior to analysis, and the project was approved by the Institutional Ethics Committee of Sichuan University. Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC)-based proteomics was employed to profile the differentially expressed proteins between a HepG2 human hepatoma cell line and an immortal hepatic cell line L02. Validation of PGAM1 expression was performed by semi-quantitative RT-PCR, immunoblot and immunohistochemistry using clinical samples. shRNA expressing plasmids specifically targeting PGAM1 were designed and constructed by GenePharma Corporation (Shanghai, China), and were utilized to silence expression of PGAM1 in vitro and in vivo. Cell proliferation was measured by a combination of colony formation assay and Ki67 staining. Apoptosis was examined by flow cytometry and TUNEL assay. RESULTS: A total of 63 dysregulated proteins were identified, including 51 up-regulated proteins, and 12 down-regulated proteins (over 2-fold, p < 0.01). Phosphoglycerate mutase 1 (PGAM1) was found markedly upregulated. Clinico-pathological analysis indicated that overexpression of PGAM1 was associated with 66.7% HCC, and strongly correlated with poor differentiation and decreased survival rates (p < 0.01). shRNAs-mediated repression of PGAM1 expression resulted in significant inhibition in liver cancer cell growth both in vitro and in vivo. CONCLUSION: Our studies suggested that PGAM1 plays an important role in hepatocarcinogenesis, and should be a potential diagnostic biomarker, as well as an attractive therapeutic target for hepatocellular carcinoma

The roles of p38mAPK and caspase-3 in dads-induced apoptosis in human HepG2 cells

The roles of p38MAPK and caspase-3 in DADS-induced apoptosis in human HepG2 cells were investigated. After the human HepG2 cells were treated with DADS, the cell viability, apoptosis and the activity changes of p38MAPK and caspase-3 were measured. The results indicated that DADS can activate p38MAPK and caspase-3. The results showed that p38MAPK and caspase-3 are involved in the process of DADS-induced apoptosis in human HepG2 cells and interact with each other

Adsorption Behavior of Fe(II) and Fe(III) Ions on Thiourea Cross-Linked Chitosan with Fe(III) as Template

A new type of thiourea cross-linked chitosan with Fe(III) as template (TCCTS template) was synthesized. The adsorption of Fe(II) and Fe(III) on this TCCTS template was studied. The factors affecting adsorption such as pH and contact time were considered. The results showed that the optimum pH value for adsorption was pH = 5.0 and the adsorption equilibrium time was about 60 min. The adsorption isotherms and kinetics were investigated, and the equilibrium data agreed very well with the Langmuir model and the pseudo second-order model could describe adsorption process better than the pseudo first-order model. Results also showed that TCCTS template was a favourable adsorbent for Fe(II) and Fe(III) in aqueous solution

Synthesis and Effect on Human HepG2 Cells of 1,2-bis- (2-Methylallyl)disulfane

molecule

DOI:10.2298/ABS1002245C THE ROLES OF P38MAPK AND CASPASE-3 IN DADS-INDUCED APOPTOSIS

Abstract- The roles of p38MAPK and caspase-3 in DADS-induced apoptosis in human HepG2 cells were investigated. After the human HepG2 cells were treated with DADS, the cell viability, apoptosis and the activity changes of p38MAPK and caspase-3 were measured. The results indicated that DADS can activate p38MAPK and caspase-3. The results showed that p38MAPK and caspase-3 are involved in the process of DADS-induced apoptosis in human HepG2 cells and interact with each other