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Sheep brain glutathione reductase was purified about 11,000-fold with an overall yield of 40%. The method included ammonium sulphate fractionation, heat denaturation, 2',5'-ADP Sepharose 4B and Sephadex G-200 chromatography steps. Specific activity at the final step was 193 IU/mg. The Mr of the enzyme was found to be 116,000 by gel filtration chromatography. On SDS-PAGE, two identical subunits of Mr 64,000 were obtained. From the spectral data, about 2 mol FAD per mol of enzyme were calculated. 相似文献
2.
Halise Inci Gul Mehtap Tugrak Hiroshi Sakagami Parham Taslimi Ilhami Gulcin Claudiu T. Supuran 《Journal of enzyme inhibition and medicinal chemistry》2016,31(6):1619-1624
A series of new 4-(3-(4-substitutedphenyl)-3a,4-dihydro-3H-indeno[1,2-c]pyrazol-2-yl) benzenesulfonamides (7–12) was synthesized starting from 2-(4-substitutedbenzylidene)-2,3-dihydro-1H-inden-1-one (1–6) and 4-hydrazinobenzenesulfonamide. The substituted benzaldehydes from which the key intermediate was prepared by introducing 2- or 4-substituents such as fluorine, hydroxy, methoxy, or the 3,4,5-trimethoxy moieties. The compounds were tested for their cytotoxicity, tumor-specificity and potential as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. The 3,4,5-trimethoxy and the 4-hydroxy derivatives showed interesting cytotoxic activities, which may be crucial for further anti-tumor activity studies, whereas some of these sulfonamides strongly inhibited both human (h) cytosolic isoforms hCA I and II. 相似文献
3.
A comparative study on effect of dietary selenium and vitamin E on some antioxidant enzyme activities of liver and brain tissues 总被引:5,自引:0,他引:5
Since selenium and vitamin E have been increasingly recognized as an essential element in biology and medicine, current research
activities in the field of human medicine and nutrition are devoted to the possibilities of using these antioxidants for the
prevention or treatment of many diseases. The present study was aimed at investigating and comparing the effects of dietary
antioxidants on glutathione reductase and glutathione peroxidase activities as well as free and protein-bound sulfhydryl contents
of rat liver and brain tissues. For 12–14 wk, both sex of weanling rats were fed a standardized selenium-deficient and vitamin
E-deficient diet, a selenium-excess diet, or a control diet. It is observed that glutathione reductase and glutathione peroxidase
activities of both tissues of the rats fed with a selenium-deficient or excess diet were significantly lower than the values
of the control group. It is also shown that free and bound sulfhydryl concentrations of these tissues of both experimental
groups were significantly lower than the control group. The percentage of glutathione reductase and glutathione peroxidase
activities of the deficient group with respect to the control were 50% and 47% in liver and 66% and 61% in the brain, respectively;
while these values in excess group were 51% and 69% in liver and 55% and 80% in brain, respectively. Free sulfhydryl contents
of the tissues in both experimental groups showed a parallel decrease. Furthermore, the decrease in protein-bound sulfhydryl
values of brain tissues were more pronounced than the values found for liver. It seems that not only liver but also the brain
is an important target organ to the alteration in antioxidant system through either a deficiency of both selenium and vitamin
E or an excess of selenium alone in the diet. 相似文献
4.
This study is aimed at investigating the inhibitory effect of cadmium ion on glutathione reductase activity of rabbit brain
and liver and the relationship of this effect with dietary selenium. For this purpose, one group of New Zealand rabbits were
fed a selenium-deficient diet, another group was fed a selenium-rich diet, and the control group was fed a normal diet. The
brain and liver tissues of these groups were investigated for the in vitro inhibitory effects of Cd2+ on glutathione reductase activity. For liver, the percentage inhibition of glutathione reductase by 40 nmol/mg protein of
Cd2+ was similar for selenium-deficient and control groups, but significantly lower in the selenium-rich group. For brain tissues,
there was no difference with respect to cadmium inhibition of glutathione reductase in all three groups. 相似文献
5.
In this study, we investigated the levels of serum Zn, Cu, Mg, Mn, Fe, ceruloplasmin (Cp), transferrin (Trf), and albumin in laryngeal carcinoma and correlated their levels with the cancer stage. The sera from 35 patients with laryngeal cancer (10 at stage II, 12 at stage III, and 13 at stage IV) were extracted before treatment and compared with those from the healthy control group (n=15). Although serum Fe and Mn concentrations were lower in the laryngeal cancer groups (for all stages) than in the control group, the difference was not statistically significant (p>0.05). The higher Cu (p<0.001) and Cp (p<0.01) and lower Zn (p<0.01), Mg (p<0.001), and Trf (p<0.01) concentrations were found in laryngeal cancer groups (for each stage) when compared to the control group. In the comparison of stages II, III, and IV (with each other), all parameters were found to be statistically not significant (p>0.05). On the other hand, no meaningful difference was found in terms of the serum albumin level. In our opinion, alterations in the level of trace elements and antioxidant proteins, important for many metabolic processes, in laryngeal cancer may not be a reason for but is, in fact, a consequence of the disease itself. 相似文献
6.
Human serum butyrylcholinesterase (BChE) has been converted into a stable but less active desensitized form when heated at
45°C for 24 h. The desensitized BChE follows Michaelis-Menten kinetics, whereas native enzyme exhibits slightly negative cooperativity
with respect to butyrylthiocholine binding. In this study, we investigated the effects of Ni2+, Co2+, and Mn2+ on the desensitized BChE. It is found that all three ions were noncompetitive inhibitors of the desensitized BChE, and K
i
values have been determined as 7.816±1.060 mM, 48.722±4.635 mM, and 84.795±5.249 mM for Ni2+, Co2+, and Mn2+, respectively. In our previous study, these ions were linear mixed-type inhibitors of the native BChE. This finding confirms
that desensitized BChE changes to a different conformation than native BChE. From the comparison of K
i
values of the trace elements, it can be said that Ni2+ is a more effective inhibitor of the desensitized BChE than Co2+ and Mn2+. 相似文献
7.
Molle V Gulten G Vilchèze C Veyron-Churlet R Zanella-Cléon I Sacchettini JC Jacobs WR Kremer L 《Molecular microbiology》2010,78(6):1591-1605
The remarkable survival ability of Mycobacterium tuberculosis in infected hosts is related to the presence of cell wall-associated mycolic acids. Despite their importance, the mechanisms that modulate expression of these lipids in response to environmental changes are unknown. Here we demonstrate that the enoyl-ACP reductase activity of InhA, an essential enzyme of the mycolic acid biosynthetic pathway and the primary target of the anti-tubercular drug isoniazid, is controlled via phosphorylation. Thr-266 is the unique kinase phosphoacceptor, both in vitro and in vivo. The physiological relevance of Thr-266 phosphorylation was demonstrated using inhA phosphoablative (T266A) or phosphomimetic (T266D/E) mutants. Enoyl reductase activity was severely impaired in the mimetic mutants in vitro, as a consequence of a reduced binding affinity to NADH. Importantly, introduction of inhA_T266D/E failed to complement growth and mycolic acid defects of an inhA-thermosensitive Mycobacterium smegmatis strain, in a similar manner to what is observed following isoniazid treatment. This study suggests that phosphorylation of InhA may represent an unusual mechanism that allows M. tuberculosis to regulate its mycolic acid content, thus offering a new approach to future anti-tuberculosis drug development. 相似文献
8.
Eryavuz Onmaz Duygu Tezcan Dilek Abusoglu Sedat Sivrikaya Abdullah Kuzu Menekse Yerlikaya Fatma Humeyra Yilmaz Sema Unlu Ali 《Amino acids》2022,54(6):877-887
Amino Acids - Behçet disease (BD) is an inflammatory, multisystemic vasculitis of unknown etiopathogenesis. However, innate and adaptive immune system involvement and immune-mediated networks... 相似文献
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