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1.
Shailesh Kumar Atma P. Dwivedi Vivek Kr. Kashyap A.K. Saxena A.K. Dwivedi Ranjana Srivastava Devi P. Sahu 《Bioorganic & medicinal chemistry letters》2013,23(8):2404-2407
Synthesis of a library of novel trans 6-methoxy-1,1-dimethyl-2-phenyl-3-aryl-2,3-dihydro-1H-inden-4-yloxy alkyl amines and their antimycobacterial activity against drug sensitive and multidrug resistant strains of Mycobacterium tuberculosis have been reported. All the new compounds in the series exhibited MIC between 1.56 and 6.25 μg/ml. Two compounds 1i and 1j with low MIC and low cytotoxicity showed significant reduction in CFU in infected mouse macrophages at 1× MIC concentration. The compound 1i inhibited the growth of M. tuberculosis in mice at 100 mg/kg dose with 1.35 log10 reduction of CFU in lungs tissue and was active against non-replicating Mycobacterium tuberculosis under anaerobic condition. 相似文献
2.
We present the three-dimensional (3D) solution structure of a calcium-binding protein from Entamoeba histolytica (EhCaBP), an etiologic agent of amoebiasis affecting millions worldwide. EhCaBP is a 14.7 kDa (134 residues) monomeric protein thought to play a role in the pathogenesis of amoebiasis. The 3D structure of Ca(2+)-bound EhCaBP has been derived using multidimensional nuclear magnetic resonance (NMR) spectroscopic techniques. The study reveals the presence of two globular domains connected by a flexible linker region spanning 8 amino acid residues. Each domain consists of a pair of helix-loop-helix motifs similar to the canonical EF-hand motif of calcium-binding proteins. EhCaBP binds to four Ca(2+) with high affinity (two in each domain), and it is structurally related to calmodulin (CaM) and troponin C (TnC) despite its low sequence homology ( approximately 29%) with these proteins. NMR-derived structures of EhCaBP converge within each domain with low RMSDs and angular order-parameters for backbone torsion angles close to 1.0. However, the presence of a highly flexible central linker region results in an ill-defined orientation of the two domains relative to one other. These findings are supported by backbone (15)N relaxation rate measurements and deuterium exchange studies, which reveal low structural order parameters for residues in the central linker region. Earlier, biochemical studies showed that EhCaBP is involved in a novel signal transduction mechanism, distinct from CaM. A possible reason for such a functional diversity is revealed by a detailed comparison of the 3D structure of EhCaBP with that of CaM and TnC. The studies indicate a more open C-terminal domain for EhCaBP with larger water exposed total hydrophobic surface area as compared to CaM and TnC. Further dissimilarities between the structures include the presence of two Gly residues (G63 and G67) in the central linker region of EhCaBP, which seem to impart it a greater flexibility compared to CaM and TnC and also play crucial role in its biological function. Thus, unlike in CaM and TnC, wherein the length and/or composition of the central linker have been found to be crucial for their function, in EhCaBP, both flexibility as well as amino acid composition is required for the function of the protein. 相似文献
3.
S P Kalra L G Allen A Sahu P S Kalra W R Crowley 《Journal of steroid biochemistry》1988,30(1-6):185-193
We report that the two classes of regulatory neuropeptides, neuropeptide Y (NPY) and endogenous opioid peptides (EOP), modulate luteinizing hormone (LH) release in diverse fashion in gonad-intact rats. Each neuropeptide acts at two loci, the hypothalamus and pituitary, to excite (NPY) or inhibit (EOP) LH release. At the hypothalamic level, NPY stimulates luteinizing hormone releasing hormone (LHRH) release, a response mediated by alpha 2-adrenoreceptors and amplified in the presence of adrenergic agonists. At the pituitary level, NPY acts in concert with LHRH to amplify the LH response. In contrast, EOP inhibit LHRH release by decreasing the supply of excitatory adrenergic signals in the vicinity of LHRH neurons in the preoptic-tuberal pathway, and at the pituitary level, they decrease LH release in response to LHRH. Further, the gonadal steroidal milieu facilitates NPY neurosecretion and postsynaptic expression of NPY in concert with adrenergic system; a similar clear-cut facilitatory effect of gonadal steroids on EOP secretion is not yet obvious. Our additional studies imply that the EOP system has the potential to increase sensitivity towards gonadal steroids and that to induce the preovulatory LH surge the neural clock may decrease the inhibitory EOP tone prior to the critical period on proestrus. This antecedent neural event allows the excitatory adrenergic and NPY signals to evoke LHRH secretion at a higher frequency approximating that seen in ovariectomized rats. Further studies are under way to delineate the steroid-induced subcellular events that integrate the action of these regulatory peptides in the control of the episodic LHRH secretion pattern which sustains basal and cyclic gonadotropin release in the rat. 相似文献
4.
5.
Experiments were conducted to determine optimum stocking density for Clarias batrachus larvae and fry during hatchery rearing. The increase in stocking density decreased the total weight, specific growth rate (SGR) and percent weight gain of Clarias larvae during a 13‐day experiment. Survival rate was highest at a stocking density of 1000 m?2 and lowest at 5000 m?2. Stocking density did not influence the total biomass production of larvae. Clarias batrachus fry performance was studied during a 28‐day hatchery rearing experiment whereby fry stocked at a density of 100 m?2 attained the highest total body weight (P < 0.05). The survival rate greatly declined to 59–61% by a density increase to 300 m?2 and above. Stocking density influenced growth and survival of C. batrachus larvae and fry during hatchery rearing. The best performance was obtained when larvae were stocked at 2000 m?2; survival was highest with C. batrachus fry stocked at 200 m?2. 相似文献
6.
Effect of high doses of cobra venom (150 micrograms/120 +/- 20 g body weight) and viper venom (300 micrograms/120 +/- 20 g body weight) on total lipid, triglyceride, phospholipid, cholesterol, high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) of brain of albino rats was studied. Total lipid (TL) triglyceride (TG) and phospholipid (PL) are decreased in both viper and cobra venom treated groups while cholesterol (C), and LDL-C are increased in both the groups in relation to controlled ones. HDL-C content was almost unaltered. Decrease in triglyceride and phospholipid may be due to effect of lipases and phospholipases whereas increased cholesterol and LDL-C may be attributed to lysis of cell membrane. 相似文献
7.
Two steroidal saponins, floribundasaponins A and B isolated from the yams of Dioscorea floribunda, have been characterized as pennogenin-3-O-β-d-glucopyranoside and pennogenin-3-O-α-l-rhamnopyranosyl(1→4)-β-d-glucopyranoside. 相似文献
8.
Mink (Mustela vison) were inoculated with viruses: African horse sickness (AHS), African swine fever (ASF), bovine herpes virus II (BHV2), foot-and-mouth disease (FMD), goat pox (GP), hog cholera (HC), peste des petits ruminants (PPR), rinderpest (RP), swine vesicular disease (SVD), vesicular exanthema of swine (VES) and vesicular stomatitis (VS). Their susceptibility was measured by development of clinical signs, virus isolation and detection of precipitin and/or virus neutralizing antibodies. SVD virus produced a lesion in one mink. Virus was isolated from mink inoculated with SVD, FMD and BHV2. Neutralizing and/or precipitin antibodies were detected in mink inoculated with ASF, FMD, GP, RP, SVD and VS viruses. Mink were not susceptible to AHS, HC, PPR and VES viruses. 相似文献
9.
Neuropeptide Y (NPY)-induced feeding behavior in female rats: comparison with human NPY ([Met17]NPY), NPY analog ([norLeu4]NPY) and peptide YY 总被引:2,自引:0,他引:2
Porcine neuropeptide Y (pNPY) administered into the third ventricle of the brain is known to elicit a powerful feeding response in steroid-treated ovariectomized and intact male rats. The present study compared the effects of pNPY and 3 structurally related peptides, human NPY (hNPY), an analog of NPY (NPY-A, [norLeu4]NPY) and peptide YY (PYY) on feeding behavior in intact female rats. Intraventricular administration of pNPY, hNPY, NPY-A and PYY over a dose range of 0.5 to 10 micrograms evoked feeding behavior to a varying extent. Cumulative food intake during 60 and 120 min was increased in a dose-related fashion at 0.5 and 2.0 microgram for the 4 peptides. Whereas the 10-micrograms dose of pNPY evoked a feeding response smaller than that seen after 2 micrograms, the responses to either 10 micrograms hNPY or 10 micrograms PYY were similar to that seen after 2 micrograms. The effects of these peptides on the time spent eating were quite different: while pNPY increased the time spent eating, this effect was not dose-related, whereas hNPY, NPY-A and PYY produced dose-related increments in the time spent eating. The most dramatic increment in local eating rate was observed after 2.0 micrograms pNPY, with lesser increments seen after 2.0 microgram hNPY and NPY-A. This increased local eating was apparently responsible for the highest cumulative food intake observed. These results demonstrate that (a) 2 micrograms pNPY is equally effective in stimulating feeding behavior in intact female rats as it is in steroid-primed ovariectomized female and intact male rats.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
10.
Epigenetic mechanisms of plant stress responses and adaptation 总被引:3,自引:0,他引:3
Pranav Pankaj Sahu Garima Pandey Namisha Sharma Swati Puranik Mehanathan Muthamilarasan Manoj Prasad 《Plant cell reports》2013,32(8):1151-1159
Epigenetics has become one of the hottest topics of research in plant functional genomics since it appears promising in deciphering and imparting stress-adaptive potential in crops and other plant species. Recently, numerous studies have provided new insights into the epigenetic control of stress adaptation. Epigenetic control of stress-induced phenotypic response of plants involves gene regulation. Growing evidence suggest that methylation of DNA in response to stress leads to the variation in phenotype. Transposon mobility, siRNA-mediated methylation and host methyltransferase activation have been implicated in this process. This review presents the current status of epigenetics of plant stress responses with a view to use this knowledge towards engineering plants for stress tolerance. 相似文献