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21.
Mazumder UK Gupta M Bhattacharya S Karki SS Rathinasamy S Thangavel S 《Journal of enzyme inhibition and medicinal chemistry》2004,19(2):185-192
These ligands (L) show a bidentate behavior, forming octahedral ruthenium complexes. The title complexes were subjected to in-vivo anticancer activity tests against a transplantable murine tumor cell line, Ehrlich's Ascitic Carcinoma (EAC) and in-vitro antibacterial activity against several Gram positive and Gram negative bacterial strains. [Ru(bpy)2(ihqs)]Cl2 and [Ru(bpy)2 (hc)]Cl2 (where bpy = 2,2'-bipyridine, ihqs = 7-iodo-8hydroxy quinoline-5-sulphonic acid and hc = 3-hydroxy coumarin) showed promising antitumor activity. Treatment with these complexes prolonged the life span of EAC bearing mice as well as decreased their tumor volume and viable ascitic cell count. All the tested complexes exhibited mild to moderate antibacterial activity. 相似文献
22.
Shenoy AR Sivakumar K Krupa A Srinivasan N Visweswariah SS 《Comparative and Functional Genomics》2004,5(1):17-38
Cyclic nucleotides are well-known second messengers involved in the regulation of important metabolic pathways or virulence factors. There are six different classes of nucleotide cyclases that can accomplish the task of generating cAMP, and four of these are restricted to the prokaryotes. The role of cAMP has been implicated in the virulence and regulation of secondary metabolites in the phylum Actinobacteria, which contains important pathogens, such as Mycobacterium tuberculosis, M. leprae, M. bovis and Corynebacterium, and industrial organisms from the genus Streptomyces. We have analysed the actinobacterial genome sequences found in current databases for the presence of different classes of nucleotide cyclases, and find that only class III cyclases are present in these organisms. Importantly, prominent members such as M. tuberculosis and M. leprae have 17 and 4 class III cyclases, respectively, encoded in their genomes, some of which display interesting domain fusions seen for the first time. In addition, a pseudogene corresponding to a cyclase from M. avium has been identified as the only cyclase pseudogene in M. tuberculosis and M. bovis. The Corynebacterium and Streptomyces genomes encode only a single adenylyl cyclase each, both of which have corresponding orthologues in M. tuberculosis. A clustering of the cyclase domains in Actinobacteria reveals the presence of typical eukaryote-like, fungi-like and other bacteria-like class III cyclase sequences within this phylum, suggesting that these proteins may have significant roles to play in this important group of organisms. 相似文献
23.
Monti P Campomenosi P Ciribilli Y Iannone R Inga A Shah D Scott G Burns PA Menichini P Abbondandolo A Gold B Fronza G 《The Journal of biological chemistry》2002,277(32):28663-28668
Due to its minor groove selectivity, Me-lex preferentially generates N3-methyladenine (3-MeA) adducts in double-stranded DNA. We undertook a genetic approach in yeast to establish the influence of base excision repair (BER) defects on the processing of Me-lex lesions on plasmid DNA that harbors the p53 cDNA as target. We constructed a panel of isogenic strains containing a reporter gene to test p53 function and the following gene deletions: deltamag1, deltaapn1apn2, and deltaapn1apn2mag1. When compared with the wild-type strain, a decrease in survival was observed in deltamag1, deltaapn1apn2, and deltaapn1apn2mag1. The Me-lex-induced mutation frequency increased in the following order: wild type < deltamag1< deltaapn1apn2 = deltaapn1apn2mag1. A total of 77 mutants (23 in wild type, 31 in deltamag1, and 23 in deltaapn1apn2) were sequenced. Eighty-one independent mutations (24 in wild type, 34 in deltamag1, and 23 in deltaapn1apn2) were detected. The majority of base pair substitutions were AT-targeted in all strains (14/23, 61% in wild type; 20/34, 59%, in deltamag1; and 14/23, 61%, in deltaapn1apn2). The Mag1 deletion was associated with a significant decrease of GC > AT transitions when compared with both the wild-type and the AP endonuclease mutants. This is the first time that the impact of Mag1 and/or AP endonuclease defects on the mutational spectra caused by 3-MeA has been determined. The results suggest that 3-MeA is critical for Me-lex cytotoxicity and that its mutagenicity is slightly elevated in the absence of Mag1 glycosylase activity but significantly higher in the absence of AP endonuclease activity. 相似文献
24.
Sivakumar A 《In silico biology》2002,2(4):507-510
2-D Gel Technology has had profound impact on proteomic research over the years. Informatics support brought a new dimension to 2D gels and associated technologies. But with advent of new and emerging technologies, it will be interesting to observe the trends of 2D gel technology in the years to come. Here we review 2D gel technology and its applications besides looking at the future scope of 2D gels in the post genome era. 相似文献
25.
Marx S Baumgärtner M Kannan S Braun HP Lang BF Burger G Kunnan S 《Molecular biology and evolution》2003,20(1):145-153
In eubacteria, the respiratory bc(1) complex (complex III) consists of three or four different subunits, whereas that of mitochondria, which have descended from an alpha-proteobacterial endosymbiont, contains about seven additional subunits. To understand better how mitochondrial protein complexes evolved from their simpler bacterial predecessors, we purified complex III of Seculamonas ecuadoriensis, a member of the jakobid protists, which possess the most bacteria-like mitochondrial genomes known. The S. ecuadoriensis complex III has an apparent molecular mass of 460 kDa and exhibits antimycin-sensitive quinol:cytochrome c oxidoreductase activity. It is composed of at least eight subunits between 6 and 46 kDa in size, including two large "core" subunits and the three "respiratory" subunits. The molecular mass of the S. ecuadoriensis bc(1) complex is slightly lower than that reported for other eukaryotes, but about 2x as large as complex III in bacteria. This indicates that the departure from the small bacteria-like complex III took place at an early stage in mitochondrial evolution, prior to the divergence of jakobids. We posit that the recruitment of additional subunits in mitochondrial respiratory complexes is a consequence of the migration of originally alpha-proteobacterial genes to the nucleus. 相似文献
26.
Sivakumar Prasanth Kumar Vilas R. Parmar Yogesh T. Jasrai Himanshu A. Pandya 《Journal of chemical biology》2015,8(3):95-105
Kinetin, a cytokinin which promotes seed germination by inhibiting the action of abscisic acid, is an important molecule known to trigger various molecular mechanisms by interacting with an array of proteins shown from experimental observations in various model organisms. We report here the prediction of most probable protein targets of kinetin from spinach proteome using in silico approaches. Inverse docking and ligand-based similarity search was performed using kinetin as molecule. The former method prioritized six spinach proteins, whereas the latter method provided a list of protein targets retrieved from several model organisms. The most probable protein targets were selected by comparing the rank list of docking and ligand similarity methods. Both of these methods prioritized chitinase as the most probable protein target (ΔGpred = 5.064 kcal/mol) supported by the experimental structure of yeast chitinase 1 complex with kinetin (PDB: 2UY5) and Gliocladium roseum chitinase complex with 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione (caffeine; 3G6M) which bears a 3D similarity of 0.43 with kinetin. An in vitro study to evaluate the effect of kinetin on spinach seed germination indicated that a very low concentration of kinetin (0.5 mg/l) did not show a significant effect compared to control in inducing seed germination process. Further, higher levels of kinetin (>0.5 mg/l) constituted an antagonist effect on spinach seed germination. It is anticipated that kinetin may have a molecular interaction with prioritized protein targets synthesized during the seed germination process and reduces growth. Thus, it appears that kinetin may not be a suitable hormone for enhancing spinach seed germination in vitro.
Electronic supplementary material
The online version of this article (doi:10.1007/s12154-015-0135-3) contains supplementary material, which is available to authorized users. 相似文献27.
Kirthiram K. Sivakumar Jone A. Stanley Joe A. Arosh Melissa E. Pepling Robert C. Burghardt Sakhila K. Banu 《Developmental biology》2014
Hexavalent chromium (CrVI), one of the more toxic heavy metals, is widely used in more than 50 industries such as chrome plating, welding, wood processing and tanneries. As one of the world?s leading producers of chromium compounds, the U.S. is facing growing challenges in protecting human health against multiple adverse effects of CrVI. CrVI is rapidly converted to CrIII intracellularly, and can induce apoptosis through different mechanisms. Our previous studies demonstrated postnatal exposure to CrVI results in a delay or arrest in follicle development and puberty. Pregnant rats were treated with 25 ppm potassium dichromate (CrVI) from gestational day (GD) 9.5 to 14.5 through drinking water, placentae were removed on GD 20, and total Cr was estimated in the placentae; ovaries were removed from the F1 offspring on postnatal day (PND)-1 and various analyses were performed. Our results show that gestational exposure to CrVI resulted in (i) increased Cr concentration in the placenta, (ii) increased germ cell apoptosis by up-regulating p53/p27–Bax–caspase-3 proteins and by increasing p53–SOD-2 co-localization; (iii) accelerated germ cell cyst (GCC) breakdown; (iv) advanced primordial follicle assembly and primary follicle transition and (v) down regulation of p-AKT, p-ERK and XIAP. As a result of the above events, CrVI induced early reproductive senescence and decrease in litter size in F1 female progeny. 相似文献
28.
Amylase inhibitor producing actinobacteria were isolated and characterized from terrestrial environment and there is no much
report found from marine environment, hence in the present study, 17 strains isolated from the rhizosphere sediments of mangroves
were tested for their amylase inhibition ability. Seawater requirement test for the growth of actinobacteria found that the
strains SSR-3, SSR-12 and SSR-16 requires at least 50% and SSR-6 requires at least 25% seawater for their growth. The inhibition
activity of both prokaryotic and eukaryotic amylase was tested by using Bacillus subtilis and Aspergillus niger. The maximum amylase activity (40mm) produced by the A. niger was taken as positive control, when the test actinobacteria strains grown in the medium they inhibited amylase activity and
was evidenced by the reduction in inhibition zone (14–37 mm) similarly the amylase produced by the Bacillus subtilis was also recorded maximum (35 mm) amylase activity and was taken as positive control, and the test atinobacterial strains
reduced enzyme action(12–33 mm) it varied levals. This indicates that the actinobacteria strains were controlled amylase enzyme
activity in both the cases. The strain SSR-10 was highly effective and SSR-8 was less effective in inhibiting eukaryotic amylase
produced by A. niger. The strain SSR-2 was effective and SSR-6 showed very less effect in inhibiting the prokaryotic amylase produced by the B subtilis. 相似文献
29.
K. Sivakumar Maloy Kumar Sahu T. Thangaradjou L. Kannan 《Indian journal of microbiology》2007,47(3):186-196
Marine actinobacteriology is one of the major emerging areas of research in tropics. Marine actinobacteria occur on the sediments
and in water and also other biomass (mangrove) and substrates (animal). These organisms are gaining importance not only for
their taxonomic and ecological perspectives, but also for their unique metabolites and enzymes. Many earlier studies on these
organisms were confined only to the temperate regions. In tropical environment, investigations on them have gained importance
only in the last two decades. So far, from the Indian peninsula, 41 species of actinobacteria belonging to 8 genera have been
recorded. The genus, Streptomyces of marine origin has been more frequently recorded. Of 9 maritime states of India, only 4 have been extensively covered for
the study of marine actinobacteria. Most of the studies conducted pertain to isolation, identification and maintenance of
these organisms in different culture media. Further, attention has been focused on studying their antagonistic properties
against different pathogens. Their biotechnological potentials are yet to be fully explored. 相似文献
30.
Kaposi's sarcoma-associated herpesvirus induces sustained NF-kappaB activation during de novo infection of primary human dermal microvascular endothelial cells that is essential for viral gene expression 下载免费PDF全文
Sadagopan S Sharma-Walia N Veettil MV Raghu H Sivakumar R Bottero V Chandran B 《Journal of virology》2007,81(8):3949-3968