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21.
We have investigated the binding of 3-[125I]iododizocilpine ([125I]iodo-MK-801) to the N-methyl-D-aspartate (NMDA) receptor in well-washed rat brain membranes. [125I]Iododizocipline binding was displaced by the following: dizocilpine greater than thienylphencyclidine greater than phencyclidine greater than ketamine. Binding of [125I]iododizocilpine was enhanced by glutamate, glycine, and spermidine, whose actions could be reversed by CGS-19755, 7-chlorokynurenate, and arcaine, respectively. [125I]Iododizocilpine binding was also enhanced by a number of divalent cations, including Ba2+, Ca2+, Mg2+, Mn2+, and Sr2+, and several monovalent cations, including Na+ and K+. These cations enhanced [125I]iododizocilpine binding by an action at the polyamine site. In addition, the inhibitory effects associated with high concentrations of these cations was markedly reduced compared to those found in previous studies with [3H]dizocilpine. Analysis of the ability of spermidine, Mg2+, and Sr2+ to alter the inhibition of [125I]iododizocilpine by arcaine gave pA2 values of 5.41, 4.47, and 4.93, corresponding to EC50 concentrations of 3.9, 34.7, and 12.0 microM, respectively, suggesting that physiological concentrations of Mg2+ may occupy the polyamine site. These results demonstrate that [125I]iododizocilpine is a useful probe for the NMDA receptor. Moreover, its high specific activity and relative insensitivity to the inhibitory actions of divalent cations should make [125I]iododizocilpine a valuable ligand for the study of NMDA receptors in intact cellular systems. 相似文献
22.
Calothrix sp. M103, enhanced by addition of iron and siderophore production was used as a biofertilizer. The strain was isolated from a colony on the surface root of a rice plant from a rice field in Bangladesh. It showed a marked and immediate increase in nitrogenase activity in response to the addition of iron and also a normal activity (compared with the control) under siderophore production. The addition of iron to iron-limited cultures resulted in a rapid increase in algal iron (11-fold) followed by a marked increase (9-fold) in nitrogenase activity, reaching about 11.8 kg N/ha/crop. This was more than twice the amount of nitrogen usually fixed by the alga during normal growth (controlled conditions), suggesting that pulsing algal inocula with iron would increase the efficiency of algae as a biofertilizer. Indeed, the use of an iron-pulsed inoculum of this strain as a biofertilizer resulted in an increase in the yield of sweetcorn by ca 143% over that produced by the control (no algal inoculation) and to ca a 73% increase over that produced by the normal inoculum (unpulsed with iron). The ability of this strain to produce siderophores has also led to both normal (compared with the control) nitrogenase activity as well as normal growth, which shows a marked contrast to other circumstances where the non-siderophore producing strains showed no growth at all. The significance of these observations on the enhancement of biofertilizer technology is discussed. 相似文献
23.
A study on biological activity measurements and heterotrophic bacteria in a small freshwater lake 总被引:1,自引:1,他引:0
A 6-m-deep lake has been sampled to measure the temporal and depth-wise distribution of heterotrophic bacteria and biological activity in the water. Surface, mid-depth and bottom waters were analysed at monthly intervals for a period of one year. The coefficient of heterotrophic activity, alkaline phosphatase activity and biological oxygen demand are used as an index of biological activity. The bacterial community was at maximum during spring, coinciding with high values of biological activity. Highest biological activity was observed in the bottom waters. Dissolved organic carbon showed a significant positive correlation with most of the biological activity parameters. This suggests that biological activity, as measured by the coefficient of heterotrophic activity, was more closely related to the concentration of substrates than to population density of heterotrophic bacteria. 相似文献
24.
A new alkaloid, 3-methoxy-4,6-dihydroxymorphinandien-7-one, and norsinoacutine have been isolated from extracts of Croton bonplandianum. 相似文献
25.
Summary Nitrosoguanidine induced blue pigment mutants of the blue-green alga Anabaena doliolum were isolated. The blue-mutants on further characterization were grouped into three developmental phenotypes — (i) those forming doli-form blue-spores of heterogenous size i.e., Ad 011, (ii) those forming spheroidal cells in the stationary phase, some of which behave like spores on transfer to fresh medium i.e., Ad 012, and (iii) those showing no sporulation and conditionally producing abnormal cells in the presence of combined nitrogen only i.e., Ad 007. The former two classes of mutants showed the formation of abnormal cells irrespective of the presence or absence of combined nitrogen sources in the medium. The formation of abnormal cells in the filaments of the above mutants were distinguished by their larger size and irregular mode of division leading to true-branch formation. The comparative characterization of these mutant strains with the parental one showed sluggish growth, increased UV-sensitivity, almost unchanged photorepair capacity, a marked change in the pigment composition and relative resistance to nitrosoguanidine. Irregular cell division in both space and time in the mutant strains and their increased sensitivity to ultraviolet irradiation indicate the possible involvement of dark repair system in maintaining the precision of cell cycle in this alga. 相似文献
26.
Synthesis of proteins rich in lysine declines progressively with endosperm development and these proteins appear to be degraded preferentially at later stages. The proteolytic enzymes in extracts of endosperms at a late stage of development release considerably more lysine radioactivity from labelled endosperm proteins as compared with the enzymes in endosperms at an early stage. 相似文献
27.
Ajay Kumar Tiwari Kavita Kumari Neeraj Nath Tiwari Pradeep Kumar Akil Ahmad Khan 《Archives Of Phytopathology And Plant Protection》2013,46(17-20):931-935
During the survey of two successive years 2012–2013, in nearby places of Gorakhpur districts, Uttar Pradesh, India, Arundo donax plants were found to be exhibiting witches’ broom, excessive branching accompanied with little leaf symptoms with considerable disease incidence. Nested PCR carried out with universal primers pair R16F2n/R16R2 employing the PCR (P1/P7) product as a template DNA (1:20) resulted in expected size positive amplification ~1.2 kb in all symptom-bearing plants suggested the association of phytoplasma with witches’ broom disease of Narkat plants. BLASTn analysis of the 16S rRNA gene sequence showed the highest (99%) sequence identity with Candidatus phytoplasma asteris (16SrI group). In phylogenetic analysis, the sequence data showed close relationships with the members of 16SrI phytoplasma and clustered within a single clade of 16SrI group and closed to B subgroup representatives. This is a first report of 16Sr I-B group phytoplasma associated with witches’ broom accompanied with little leaf disease of Narkat in India. 相似文献
28.
Susanne Siebentritt Enrico Avancini Marcus Br Jakob Bombsch Emilie Bourgeois Stephan Buecheler Romain Carron Celia Castro Sebastien Duguay Roberto Flix Evelyn Handick Dimitrios Hariskos Ville Havu Philip Jackson Hannu‐Pekka Komsa Thomas Kunze Maria Malitckaya Roberto Menozzi Milos Nesladek Nicoleta Nicoara Martti Puska Mohit Raghuwanshi Philippe Pareige Sascha Sadewasser Giovanna Sozzi Ayodhya Nath Tiwari Shigenori Ueda Arantxa Vilalta‐Clemente Thomas Paul Weiss Florian Werner Regan G. Wilks Wolfram Witte Max Hilaire Wolter 《Liver Transplantation》2020,10(8)
29.
30.
Kumar Ritesh Khungar Lisha Shimphrui Rinchuila Tiwari Lalit Dev Tripathi Gayatri Sarkar Neelam K. Agarwal Surekha-Katiyar Agarwal Manu Grover Anil 《Journal of plant biochemistry and biotechnology.》2020,29(4):715-732
Journal of Plant Biochemistry and Biotechnology - Caseinolytic protease (Clp)/Hsp100 proteins are members of the AAA+ (ATPase associated with a variety of cellular activities) family of proteins... 相似文献