Human serum arylesterase and glutathione s-transferase activities in patients with ischemic stroke compared to healthy controls

Türkanoğlu, Aysun
Stroke is an important public health problem and the third leading cause of death after coronary heart diesase and all cancers in all over the world. Free radicals and oxidative stress play important role in the pathogenesis of several diseases including atherosclerosis, stroke, cancer, neurodegenerative diseases such as Alzheimer's dementia. The activity of paraoxonase (PON1) aganist phenylacetate is known as arylesterase (ARE). Paraoxonase is an esterase associated with high-density lipoprotein (HDL) and contributes to the protective role of this lipoprotein on low-density lipoprotein (LDL) oxidation. Oxidized LDL is known to play a central role in early events in the progression of atherosclerosis which is a risk factor for stroke. Glutathione S-transferases (GSTs) catalyze the conjugation of nonpolar compounds to reduced glutathione (GSH) and detoxify toxic metabolites produced within the cell by oxidative stress to protect cells from oxidant injury. v The maximum ARE enzyme activity was detected at 10 mM Tris-HCl buffer, pH 8.0 and at 45 °C. ARE enzyme was saturated with its substrate phenylacetate around 20 mM concentration. The apparent Km and Vmax values of human blood serum ARE for phenylacetate were found as 1.66 mM and 3300 nmol/min/mg, respectively. The maximum GST enzyme activity was detected at 2 mM potassium phosphate buffer, pH 5.5 and at 65 °C. GST enzyme was saturated with its substrate, CDNB around 4.5 mM concentration and with its cofactor, GSH around 8 mM concentration. The apparent Km and Vmax values of human blood serum GST for CDNB substrate were found as 2.8 mM and 0.43 nmol/min/mg and for GSH were found as 4.11 mM and 0.23 nmol/min/mg, respectively. In addition, effects of three different heavy metal ions, Cd+2, Hg+2 and Ni+2, on human blood serum ARE and GST activity were studied and half maximal inhibitory concentrations (IC50) were determined. The main objective of this study was to investigate the human blood serum ARE and GST activities in patient and control groups using the optimized conditions. For this purpose, blood samples were collected from 172 ischemic stroke patients and 105 controls. Then serum obtained from blood samples were used to determine ARE and GST activities. The mean of ARE activity in patient group (n=172, 109.9 ± 32.5 U/mL ) was insignificantly lower than the mean of ARE activity in control group (n=105, 113.5 ± 33.1 U/mL, P=0.284). GST activity of the patients (10.8 ± 4.4 U/L) was insignificantly higher than that of controls (10.5 ± 4.2 U/L, P=0.483 ). In addition, statistical analysis showed hypertension, diabetes and HDL as significant risk factors of stroke.


The serum immunoglobulin G glycosylation signature of gastric cancer
Ruhaak, L. Renee; Barkauskas, Donald A.; Torres, Javier; Cooke, Cara L.; Wu, Lauren D.; Stroble, Carol; Özcan Kabasakal, Süreyya; Williams, Cynthia C.; Camorlinga, Margarita; Rocke, David M.; Lebrilla, Carlito B.; Solnick, Jay V. (Elsevier BV, 2015-03-01)
Biomarkers may facilitate detection of gastric cancer at an earlier stage and reduce mortality. Here we sought to determine if the glycosylation profile of serum immunoglobulin G (IgG) could distinguish patients with non-atrophic gastritis (NAG), duodenal ulcer (DU) and gastric cancer (GC). Serum IgG was released and analyzed using nano-LC–TOF mass spectrometry. Statistically significant false discovery rate (FDR)-adjusted p-values were observed for 18 glycans, eight that differed significantly between NAG ...
The effects of selenium on stz-induced diabetic rat kidney plasma membrane
Gurbanov, Rafig; Severcan, Feride; Department of Biochemistry (2010)
The kidney is one of the most affected organs of body from diabetes. Diabetic kidney disease is a complication of diabetes seen in 30-40% of diabetic person. The aim of this work is to contribute the useful information in the therapy of diabetes. It is very important to know the role of antioxidants at the molecular level during diabetes. The protecting role of antioxidants against lipid peroxidation, the effect of cellular antioxidant enzyme systems, understanding the changes of membrane fluidity, lipid or...
The expression of gst genes in diabetic rat liver tissues
İrtem Kartal, Deniz; Güray, Tülin; Department of Biochemistry (2008)
Free radicals which have critical roles in living systems through their beneficial and detrimental effects play an important role in medical revolution in health. Radicals are produced in the cells and tissues of our bodies by various processes and reactions. Diabetes mellitus is an extremely common disease in the world which seems to be accompanied by a shortage of antioxidants and an increase in free radicals, the end result of oxidative stress. Glutathione S-Transferases (GST; EC are found in e...
Enzyme-catalyzed reductive activation of anticancer drugs ıdarubicin and mitomycin c
Çelik, Haydar; Arınç, Emel; Department of Biochemistry (2008)
Idarubicin (IDA) and mitomycin C (MC) are clinically effective quinone-containing anticancer agents used in the treatment of several human cancers. Quinone-containing anticancer drugs have the potential to undergo bioreduction by oxidoreductases to reactive species, and thereby exert their cytotoxic effects. In the present study, we investigated, for the first time, the potential of IDA, in comparison to MC, to undergo reductive activation by NADPH-cytochrome P450 reductase (P450R), NADH-cytochrome b5 reduc...
Examination of the dielectrophoretic spectra of MCF7 breast cancer cells and leukocytes
Çağlayan, Zeynep; Demircan Yalçın, Yağmur; Külah, Haluk (Wiley, 2020-03-01)
The detection of circulating tumor cells (CTCs) in blood is crucial to assess metastatic progression and to guide therapy. Dielectrophoresis (DEP) is a powerful cell surface marker-free method that allows intrinsic dielectric properties of suspended cells to be exploited for CTC enrichment/isolation from blood. Design of a successful DEP-based CTC enrichment/isolation system requires that the DEP response of the targeted particles should accurately be known. This paper presents a DEP spectrum method to inve...
Citation Formats
A. Türkanoğlu, “Human serum arylesterase and glutathione s-transferase activities in patients with ischemic stroke compared to healthy controls,” M.S. - Master of Science, Middle East Technical University, 2007.