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排序方式: 共有494条查询结果,搜索用时 15 毫秒
221.
222.
Rakesh Kumar Majhi Ashutosh Kumar Manoj Yadav Nirlipta Swain Shikha Kumari Ashish Saha Avinash Pradhan Luna Goswami Somdatta Saha Luna Samanta Apratim Maity Tapas Kumar Nayak Subhasis Chattopadhyay Chitra Rajakuberan Abhishek Kumar Chandan Goswami 《Channels (Austin, Tex.)》2013,7(6):483-492
Sperm cells exhibit extremely high sensitivity in response to slight changes in temperature, osmotic pressure and/or presence of various chemical stimuli. In most cases throughout the evolution, these physico-chemical stimuli trigger Ca2+-signaling and subsequently alter structure, cellular function, motility and survival of the sperm cells. Few reports have recently demonstrated the presence of Transient Receptor Potential (TRP) channels in the sperm cells from higher eukaryotes, mainly from higher mammals. In this work, we have explored if the sperm cells from lower vertebrates can also have thermo-sensitive TRP channels. In this paper, we demonstrate the endogenous presence of one specific thermo-sensitive ion channel, namely Transient Receptor Potential Vanilloid family member sub type 1 (TRPV1) in the sperm cells collected from fresh water teleost fish, Labeo rohita. By using western blot analysis, fluorescence assisted cell sorting (FACS) and confocal microscopy; we confirm the presence of this non-selective cation channel. Activation of TRPV1 by an endogenous activator NADA significantly increases the quality as well as the duration of fish sperm movement. The sperm cell specific expression of TRPV1 matches well with our in silico sequence analysis. The results demonstrate that TRPV1 gene is conserved in various fishes, ranging from 1–3 in copy number, and it originated by fish-specific duplication events within the last 320 million years (MY). To the best of our knowledge, this is the first report demonstrating the presence of any thermo-sensitive TRP channels in the sperm cells of early vertebrates as well as of aquatic animals, which undergo external fertilization in fresh water. This observation may have implications in the aquaculture, breeding of several fresh water and marine fish species and cryopreservation of fish sperms. 相似文献
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Shikha Shikha Jonathan L Huot Andr Schneider Moritz Niemann 《Nucleic acids research》2020,48(21):12269
Mitochondrial tRNA import is widespread, but mechanistic insights of how tRNAs are translocated across mitochondrial membranes remain scarce. The parasitic protozoan T. brucei lacks mitochondrial tRNA genes. Consequently, it imports all organellar tRNAs from the cytosol. Here we investigated the connection between tRNA and protein translocation across the mitochondrial inner membrane. Trypanosomes have a single inner membrane protein translocase that consists of three heterooligomeric submodules, which all are required for import of matrix proteins. In vivo depletion of individual submodules shows that surprisingly only the integral membrane core module, including the protein import pore, but not the presequence-associated import motor are required for mitochondrial tRNA import. Thus we could uncouple import of matrix proteins from import of tRNAs even though both substrates are imported into the same mitochondrial subcompartment. This is reminiscent to the outer membrane where the main protein translocase but not on-going protein translocation is required for tRNA import. We also show that import of tRNAs across the outer and inner membranes are coupled to each other. Taken together, these data support the ‘alternate import model’, which states that tRNA and protein import while mechanistically independent use the same translocation pores but not at the same time. 相似文献
225.
Ranjan R Chugh M Kumar S Singh S Kanodia S Hossain MJ Korde R Grover A Dhawan S Chauhan VS Reddy VS Mohmmed A Malhotra P 《Journal of proteome research》2011,10(2):680-691
Plasmodium merozoite surface protein-1 (MSP-1) is an essential antigen for the merozoite invasion of erythrocytes. A key challenge to the development of an effective malaria vaccine that can block the erythrocyte invasion is to establish the molecular interaction(s) among the parasite surface proteins as well as with the host cell encoded receptors. In the present study, we applied molecular interactions and proteome approaches to identify PfMSP-1 associated complex on the merozoite surface. Proteomic analysis identified a major malaria surface protein, PfRhopH3 interacting with PfMSP-1(42). Pull-down experiments with merozoite lysate using anti-PfMSP-1 or anti-PfRhopH3 antibodies showed 16 bands that when identified by tandem mass spectrometry corresponded to11 parasite proteins: PfMSP-3, PfMSP-6, PfMSP-7, PfMSP-9, PfRhopH3, PfRhopH1, PfRAP-1, PfRAP-2, and two RAP domain containing proteins. This MSP-1 associated complex was specifically seen at schizont/merozoite stages but not the next ring stage. We could also identify many of these proteins in culture supernatant, suggesting the shedding of the complex. Interestingly, the PfRhopH3 protein also showed binding to the human erythrocyte and anti-PfRhopH3 antibodies blocked the erythrocyte invasion of the merozoites. These results have potential implications in the development of PfMSP-1 based blood stage malaria vaccine. 相似文献
226.
Shikha Mehta Prashant Kumar Rai Nilesh Kumar Rai A. K. Rai Dane Bicanic Geeta Watal 《Food biophysics》2011,6(4):497-502
This paper reports, the Laser Induced Breakdown Spectroscopy (LIBS) studies and structure elucidation of compounds isolated
from the fruit extract of Moringa oleifera and also deals with their possible effects on some bacterial strains viz. Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli and Pseudomonas aeruginosa. The extract was found to be active against all four microorganisms used. Extent of inhibitory effect of extract was assessed
at different concentrations of 25, 50, 75 mg/ml by measuring diameter of inhibition zone (DIZ). Our results clearly showed
that the 75 mg/ml concentration of the extract had 14, 12 and 18 mm of the DIZ against Staphylococcus aureus, Klebsiella pneumonia and Pseudomonas aeruginosa and 14 mm with 50 mg/ml concentration against Escherichia coli. The results were compared with the standard antibiotic ‘ampicillin’ of 1 mg/ml concentration. LIBS was recorded with high
power pulsed laser beam from Nd: YAG Laser (Continuum Surelite III-10), focused on the surface of the material, which was
in liquid form, to generate plasma on the surface of the sample. LIBS data clearly demonstrate the presence of trace elements,
magnesium and iron, in high concentration in the extract. Whereas, from the phytochemical profile reveals the presence of
two new compounds, S-ethyl-N-{4-[(α-L-rhamnosyloxy) benzyl]} thiocarbamate and 2-acetoxy {4-[(2′,3′,4′-tri-O-acetyl-α-L-rhamnosyloxy)
benzyl]} acetonitrile as the major constituents. This study is the first report on synergetic effect of the phytoconstituents
and certain set of elements present in their defined role in bacterial management against different bacterial strains. 相似文献
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229.
Dzierba CD Sielecki TM Arvanitis AG Galka A Johnson TL Takvorian AG Rafalski M Kasireddy-Polam P Vig S Dasgupta B Zhang G Molski TF Wong H Zaczek RC Lodge NJ Combs AP Gilligan PJ Trainor GL Bronson JJ Macor JE 《Bioorganic & medicinal chemistry letters》2012,22(15):4986-4989
Pyrido[3,2-b]pyrazin-3(4H)-ones and pteridin-7(8H)-ones were evaluated as corticotropin-releasing factor-1 receptor antagonists. The synthesis, SAR studies and pharmacokinetic evaluation of these analogs are described herein. 相似文献
230.
Kumar A Shah BA Singh S Hamid A Singh SK Sethi VK Saxena AK Singh J Taneja SC 《Bioorganic & medicinal chemistry letters》2012,22(1):431-435
Boswellic acid acylates including their epimers were synthesized and screened against a panel of human cancer cell lines. They exhibited a range of cytotoxicity against various human cancer cell lines thereby leading to the development of a possible SAR. One of the identified lead compounds was found to be an inhibitor of the NF-κB and STAT proteins, warranting further investigations to be developed into a potential anticancer lead. 相似文献