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471.
Ashish Kumar Srivastava Poonam Bhargava Lal Chand Rai 《World journal of microbiology & biotechnology》2005,21(6-7):1291-1298
Summary This study provides first-hand information on the salinity and copper-induced oxidative damage and its protection in Anabaena doliolum by the antioxidant defence system. Oxidative damage measured in terms of lipid peroxidation, electrolyte leakage and H2O2 production was induced by different concentrations of NaCl and Cu2+. A greater electrolyte leakage by NaCl than Cu2+ supported the hypothesis of salinity being more injurious than copper. To explore the survival strategies of A. doliolum under NaCl and Cu stress, enzymatic antioxidant activities e.g. superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase
(APX), and glutathione reductase (GR) and nonenzymatic antioxidant contents such as glutathione reduced (GSH), ascorbate,
α-tocopherol, and carotenoid were measured. A general induction in SOD and APX activities as well as ascorbate and α-tocopherol
contents was found under NaCl and Cu2+ stress. In contrast to this, an appreciable decline in GR activity, GSH pool and carotenoid content under Cu2+ and an increase under NaCl stress were observed. CAT activity was completely inhibited at high doses of NaCl but stimulated
following Cu2+ treatment. The above results suggest the involvement of APX and CAT in the scavenging of H2O2 under Cu2+ stress. In contrast to this, only APX was involved in H2O2 scavenging under salt stress. Our postulate of Cu2+-mediated antagonism of salt stress can be explained by a conceivable reversion of Na+-induced disturbance of cellular homeostasis by redox active Cu2+. 相似文献
472.
473.
474.
Rohini Dwivedi Priyanka Samanta Poonam Sharma Fuming Zhang Sushil K. Mishra Pavel Kucheryavy Seon Beom Kim AyoOluwa O. Aderibigbe Robert J. Linhardt Ritesh Tandon Robert J. Doerksen Vitor H. Pomin 《The Journal of biological chemistry》2021,297(4)
Certain sulfated glycans, including those from marine sources, can show potential effects against SARS-CoV-2. Here, a new fucosylated chondroitin sulfate (FucCS) from the sea cucumber Pentacta pygmaea (PpFucCS) (MW ∼10–60 kDa) was isolated and structurally characterized by NMR. PpFucCS is composed of {→3)-β-GalNAcX-(1→4)-β-GlcA-[(3→1)Y]-(1→}, where X = 4S (80%), 6S (10%) or nonsulfated (10%), Y = α-Fuc2,4S (40%), α-Fuc2,4S-(1→4)-α-Fuc (30%), or α-Fuc4S (30%), and S = SO3−. The anti-SARS-CoV-2 activity of PpFucCS and those of the FucCS and sulfated fucan isolated from Isostichopus badionotus (IbFucCS and IbSF) were compared with that of heparin. IC50 values demonstrated the activity of the three holothurian sulfated glycans to be ∼12 times more efficient than heparin, with no cytotoxic effects. The dissociation constant (KD) values obtained by surface plasmon resonance of the wildtype SARS-CoV-2 spike (S)-protein receptor-binding domain (RBD) and N501Y mutant RBD in interactions with the heparin-immobilized sensor chip were 94 and 1.8 × 103 nM, respectively. Competitive surface plasmon resonance inhibition analysis of PpFucCS, IbFucCS, and IbSF against heparin binding to wildtype S-protein showed IC50 values (in the nanomolar range) 6, 25, and 6 times more efficient than heparin, respectively. Data from computational simulations suggest an influence of the sulfation patterns of the Fuc units on hydrogen bonding with GlcA and that conformational change of some of the oligosaccharide structures occurs upon S-protein RBD binding. Compared with heparin, negligible anticoagulant action was observed for IbSF. Our results suggest that IbSF may represent a promising molecule for future investigations against SARS-CoV-2. 相似文献
475.
Studies were carried out on 4-aminobenzenesulfonate (4-ABS) degradation by free and alginate entrapped cells of Agrobacterium sp. PNS-1. Degradation rate in batch reactors with free cells was marginally higher than Ca-encapsulated cells. Comparison of Ca2+ and Ba2+ as gelling agents showed that 4-ABS removal rate was significantly less with Ba-alginate entrapped cells. Specific degradation rates, using linear regression analysis and based on the initial biomass in the beads, varied from 49.7 mg/mg biomass/h to 92.0 mg/mg biomass/h for Ca-alginate encapsulated cells for different initial 4-ABS concentrations ranging from 200 to 800 mg/L. UV spectra of the aliquots drawn at different time intervals from batch reactors did not show accumulation of any intermediate during degradation. Ca-alginate immobilized cells could be repeatedly reused upto five cycles without any loss of activity. Studies with packed bed reactors, operated in a semi-continuous mode, showed that this could be used for 4-ABS degradation. 相似文献
476.
Kainthla RP Kashyap RS Prasad S Purohit HJ Taori GM Daginawala HF 《In vitro cellular & developmental biology. Animal》2006,42(10):287-289
Summary The proliferative capacity of T cells in response to various stimuli is commonly determined by radioactive assay based on
incorporation of [3H]thymidine ([3H]TdR) into newly synthesized DNA. In order to assess techniques for application in laboratories
where radioactive facilities are not present, an alternative method was tested. As an alternative, T-cell proliferation was
measured by spectrophotometrically analyzing the presence of an enzyme adenosine deaminase in lymphocytes and also using a
standard XTT assay. Jurkat (human) T-cell line (clone E6.1) was used for lymphocyte population. The Jurkat cell concentration
was adjusted according to different cell densities and enzyme activity was determined. Cells were also seeded in complete
medium up to 72 h and harvested for estimation of enzyme activity. A significant correlation between the standard cell-proliferation
assay and adenosine deaminase assay was observed. The present study indicates that the assay of adenosine deaminase is a reliable
and accurate method for measuring proliferation of T lymphocytes. 相似文献
477.
Yogesh Mishra Poonam Bhargava Riti Thapar Ashish Kumar Srivastava Lal Chand Rai 《World journal of microbiology & biotechnology》2008,24(12):2997-3004
This study provides first hand comparative account of growth and antioxidative defense system of the wild type, Cu2+ and temperature treated wild type and acclimated strains of Anabaena doliolum Bharadwaja against Cu2+ and high temperature. The acclimated strains showed perceptible growth at 250 μM Cu2+ and 47°C temperatures, respectively. In contrast to this the wild type strain on exposure to 50 μM Cu2+ and 47°C temperature depicted almost complete inhibition of growth. However, the peroxide content was significantly higher
in the acclimated strains than the wild type. Superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and
glutathione reductase (GR) showed maximum activity at high temperature followed by Cu2+ acclimated and minimum in the wild type strains. The ascorbate (ASC) and glutathione (GSH) contents were increased by 2.3
and 43.3, and 15.5 and 36.5-fold in Cu2+ and 47°C acclimated strains, respectively. However, when the wild type strain was subjected to Cu2+ and temperature all antioxidative enzymes except SOD showed inhibition of their activity. In case of wild type the GSH content
was inhibited by 0.39-fold at 50 μM Cu2+ but the ASC content registered increase by 2 and 2.7-fold on subjecting to Cu2+ and temperature, respectively. Thus increased activity of enzymatic antioxidants as well as accumulation of ascorbate and
glutathione in both the acclimated strains suggests that enzymatic and non-enzymatic antioxidants help in the acclimation
of A. doliolum Bharadwaja against Cu2+ and high temperature. However, inhibition of antioxidative defense system of wild type under Cu2+ and heat stress appears to be the reason for its non survival. In view of the appreciable increase in the level of antioxidants
as well as greater inhibition of specific growth rate in temperature than Cu2+ acclimated strains, temperature (47°C) is proposed to be is more deleterious to the organism than copper (250 μM). 相似文献
478.
Surjeet Singh Poonam Singh S. K. Awasthi Anjali Pandey Leela Iyengar 《World journal of microbiology & biotechnology》2008,24(6):841-847
A variety of environmental inocula were tested for the development of 2-aminobenzenesulfonate (2-ABS, Orthanilic acid) degrading
bacterial enrichment. A bacterial consortium (BC), which could utilize 2-ABS as the sole carbon and energy source, could only
be developed from the sludge derived from a wastewater treatment unit of a large chemical industry manufacturing nitro and
aminoaromatics. BC consisted of two bacterial strains. Based on 16S rDNA sequence analysis, these strains were identified
to be belonging to the genus, Acinetobacter and Flavobacterium. The consortium could degrade 1,000 mg l−1 2-ABS within 40 h. Evidence for the extensive mineralization of 2-ABS, during the growth of BC, was derived from U.V-spectral
and total organic carbon analysis. BC was highly specific for 2-ABS, as other benzene sulfonates tested in this study, including
other ABS isomers, were not utilized as growth substrates. 2-ABS removal pattern in the presence of glucose was significantly
influenced by acclimation characteristics of the culture. Consortium adapted to 2-ABS/glucose demonstrated the concomitant
removal of both substrates, whereas glucose exerted catabolic repression on 2-ABS removal with glucose adapted culture. Presence
of chloramphenicol inhibited 2-ABS degradation by cells, pregrown on succinate, indicating that the 2-ABS degrading enzymes
are inducible in nature. Thus the presence of 2-ABS is essential for maintaining the high degradation potential. This enrichment
culture can find an application in the treatment of 2-ABS containing wastewaters. 相似文献
479.
Srivastava P Bhattacharaya P Pandey G Mukherjee KJ 《Protein expression and purification》2005,41(2):313-322
Overexpression of rhIFN-alpha2b was obtained by synthesizing a codon optimized gene for IFN-alpha2b and expressing it in the form of inclusion bodies (IBs) in Escherichia coli. The recombinant plasmid pRSET-IFNalpha, which had the IFN-alpha2b gene under the T7 promoter, was coexpressed with plasmid pGP1-2, which carried the gene for T7 RNA polymerase under the heat inducible lambdaP(L) promoter. This two plasmid expression system was optimized with respect to heat shock time, media, and time of induction in shake flask cultures. This was then scaled up into a bioreactor to get a maximum volumetric product yield of 5.2g/L at a final OD(600) of 67. At this point, the IBs represented approximately 40% of the total cellular protein. This high specific product yields eased the further downstream processing steps and improved product recoveries. The IBs were isolated and purified through ion exchange followed by step refolding to give a final product yield of approximately 3g/L, which is maximum reported in the literature. The bioassay of the refolded protein gave a specific activity of approximately 3 x 10(9)IU/mg protein. 相似文献
480.
Biomarkers in risk assessment of asbestos exposure 总被引:3,自引:0,他引:3
Bhattacharya K Dopp E Kakkar P Jaffery FN Schiffmann D Jaurand MC Rahman I Rahman Q 《Mutation research》2005,579(1-2):6-21
Developments in the field of molecular epidemiology and toxicology have given valuable tools for early detection of impending disease or toxic condition. Morbidity due to respiratory distress, which may be due to environmental and occupational exposure, has drawn attention of researchers worldwide. Among the occupational exposure to respiratory distress factors, fibers and particles have been found to be main culprits in causing diseases like asbestosis, pleural plaques, mesotheliomas and bronchogenic carcinomas. An early detection of the magnitude of exposure or its’ effect using molecular end points is of growing importance. The early inflammatory responses like release of the inflammatory cells collected by non-invasive methods give an indication of the unwanted exposure and susceptibility to further complications. Since free radicals like O2−, OH, OOH, NO, NOO, etc. are involved in the progression of asbestos-related diseases and lead to cytogenetic changes, an evaluation of antioxidant states reducing equivalents like GSH and ROS generation can be a good biomarker. The cytogenetic end points like chromosomal aberration, micronucleus formation and sister chromatid exchange give indication of genetic damage, hence they are used as effective biomarkers. New techniques like fluorimetric analysis of DNA unwinding, alkaline elution test, fluorescent in situ hybridization and comet assay are powerful tools for early detection of initiation of disease process and may help in planning strategies for minimizing morbidity related to asbestos fiber exposure. The present review article covers in detail possible biomarkers for risk assessment of morbidity due to fibers/particles in exposed population. 相似文献