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991.
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993.
Zongli Li Matthew L. Baker Wen Jiang Mary K. Estes B. V. Venkataram Prasad 《Journal of virology》2009,83(4):1754-1766
Rotavirus, a nonturreted member of the Reoviridae, is the causative agent of severe infantile diarrhea. The double-stranded RNA genome encodes six structural proteins that make up the triple-layer particle. X-ray crystallography has elucidated the structure of one of these capsid proteins, VP6, and two domains from VP4, the spike protein. Complementing this work, electron cryomicroscopy (cryoEM) has provided relatively low-resolution structures for the triple-layer capsid in several biochemical states. However, a complete, high-resolution structural model of rotavirus remains unresolved. Combining new structural analysis techniques with the subnanometer-resolution cryoEM structure of rotavirus, we now provide a more detailed structural model for the major capsid proteins and their interactions within the triple-layer particle. Through a series of intersubunit interactions, the spike protein (VP4) adopts a dimeric appearance above the capsid surface, while forming a trimeric base anchored inside one of the three types of aqueous channels between VP7 and VP6 capsid layers. While the trimeric base suggests the presence of three VP4 molecules in one spike, only hints of the third molecule are observed above the capsid surface. Beyond their interactions with VP4, the interactions between VP6 and VP7 subunits could also be readily identified. In the innermost T=1 layer composed of VP2, visualization of the secondary structure elements allowed us to identify the polypeptide fold for VP2 and examine the complex network of interactions between this layer and the T=13 VP6 layer. This integrated structural approach has resulted in a relatively high-resolution structural model for the complete, infectious structure of rotavirus, as well as revealing the subtle nuances required for maintaining interactions in such a large macromolecular assembly. 相似文献
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Magnaporthe oryzae and Rhizoctonia solani, are among the most important pathogens of rice, severely limiting its productivity. Dm-AMP1, an antifungal plant defensin from Dahlia merckii, was expressed in rice (Oryza sativa L. sp. indica cv. Pusa basmati 1) using Agrobacterium tumefaciens-mediated transformation. Expression levels of Dm-AMP1 ranged from 0.43% to 0.57% of total soluble protein in transgenic plants. It was observed that constitutive expression of
Dm-AMP1 suppresses the growth of M. oryzae and R. solani by 84% and 72%, respectively. Transgenic expression of Dm-AMP1 was not accompanied by an induction of pathogenesis-related (PR) gene expression, indicating that the expression of DmAMP1
directly inhibits the pathogen. The results of in vitro, in planta and microscopic analyses suggest that Dm-AMP1 expression has the potential to provide broad-spectrum disease resistance in rice. 相似文献
997.
Ganji Purna Chandra Nagaraju Nunna Siva Kumari Ganji Lakshmi Vara Prasad Balney Rajitha Madan Meenu Manam Sreenivasa Rao Bannoth Reddya Naik 《Bioinformation》2009,4(1):6-11
The tentative elucidation of the 3D-structure of vitellogenesis inhibiting hormone (VIH)
peptides is conversely underprivileged by difficulties in gaining enough peptide or protein,
diffracting crystals, and numerous extra technical aspects. As a result, no structural
information is available for VIH peptide sequences registered in the Genbank. In this
situation, it is not surprising that predictive methods have achieved great interest. Here, in
this study the molt-inhibiting hormone (MIH) of the kuruma prawn (Marsupenaeus
japonicus) is used, to predict the structure of four VIHrelated peptides in the
crustacean species. The high similarity of the 3D-structures and the calculated physiochemical
characteristics of these peptides suggest a common fold for the entire family. 相似文献
998.
K. Samuel D. Debashish B. Madhumita G. Padmaja Siva Ram Prasad V. Bhaskara Ramana Murthy P. S. Rao 《In vitro cellular & developmental biology. Plant》2009,45(4):466-473
The propagation of Givotia rottleriformis Griff. is difficult as a result of long seed dormancy associated with poor seed germination. The present study was undertaken
to develop a protocol to overcome seed dormancy by culture of zygotic embryo axes and then develop an efficient method for
micropropagation of Givotia. Best germination frequency (78.3%) was achieved from mature zygotic embryo axes isolated from acid-scarified fresh seeds
when cultured on Murashige and Skoog (MS) medium (half-strength major salts) with 28.9 μM gibberellic acid (GA3). Efficient plant conversion was achieved by transfer of 10-d-old germinated embryos to MS medium (half-strength major salts)
supplemented with 1.2 μM kinetin (KN) and 0.5 μM indole-3-butyric acid (IBA). However, acid scarification of 1-yr-old seeds
decreased the germination frequency of zygotic embryo axes in comparison to those obtained from non-acid-scarified seeds which
germinated (96.2%) and converted into plants (80.3%) on MS basal (half-strength major salts) medium. Multiple shoot bud induction
was achieved by culture of shoot tips derived from in vitro germinated seedlings on MS medium with 0.5 μM thidiazuron for 4 wk, and the shoots elongated after transfer to a secondary
medium with 1.2 μM KN. A maximum number of 7.8 shoots per explant with an average shoot length of 3.2 cm was achieved after
two subcultures on this medium. The in vitro regenerated shoots rooted (41.5%) on half-strength MS medium with 0.5 μM IBA. The in vitro generated seedlings and micropropagated plants were established in soil with a survival frequency of 70% and 60%, respectively. 相似文献
999.
Prejwltta Maurya Preeti Sharma Lalit Mohan Lata Batabyal C.N. Srivastava 《Journal of Asia》2009,12(2):113-115
The larvicidal effect of the crude carbon tetrachloride, methanol and petroleum ether leaf extracts of a widely grown medicinal plant, Ocimum basilicum, against Anopheles stephensi and Culex quinquefasciatus was evaluated. Petroleum ether extract was found to be the most effective against the larvae of both mosquitoes, with LC50 values of 8.29, 4.57; 87.68, 47.25 ppm and LC90 values of 10.06, 6.06; 129.32, 65.58 ppm against A. stephensi and C. quinquefasciatus being observed after 24 and 48 h of treatment, respectively. The efficacy of petroleum ether was followed by that of the carbon tetrachloride and methanol extracts, which had LC50 values of 268.61, 143.85; 446.61, 384.84 ppm and LC90 values of 641.23, 507.80; 923.60, 887.00 ppm against A. stephensi after 24 and 48 h, respectively, and LC50 values of 24.14, 17.02; 63.48, 53.77 ppm and LC90 values of 295.38, 204.23; 689.71, 388.87 ppm against C. quinquefasciatus after 24 and 48 h of treatment, respectively. These extracts are highly toxic against mosquito larvae from a range of species; therefore, they may be useful for the management of mosquito larvae to control vector borne diseases. 相似文献
1000.
Rishiram Ramanan Krishnamurthi Kannan Nadimuthu Vinayagamoorthy Kunga Mohan Ramkumar Saravana Devi Sivanesan Tapan Chakrabarti 《Biotechnology and Bioprocess Engineering》2009,14(1):32-37
Carbonic anhydrase enzyme, one of the fastest known enzymes, remains largely unexplored in prokaryotes when compared to its
mammalian counterparts despite its ubiquity. In this study, the enzyme has been purified from Bacillus subtilis SA3 using sequential Sephadex G-75 chromatography, DEAE cellulose chromatography, and sepharose-4B-L-tyrosinesulphanilamide
affinity chromatography and characterized to provide additional insights into its properties. The apparent molecular mass
of carbonic anhydrase obtained by SDS-PAGE was found to be approximately 37 kDa. Isoelectric focusing of the purified enzyme
revealed an isoelectric point (pI) of around 6.1 when compared with marker. The presence of metal ions such as Zn2+, Co2+, Cu2+, Fe3+, Mg2+, and anion SO4− increased enzyme activity while strong inhibition was observed in the presence of Hg2+, Cl−, HCO3−, and metal chelator EDTA. The optimum pH and temperature for the enzyme were found to be 8.3 and 37°C, respectively. Enzyme
kinetics with p-nitrophenyl acetate as substrate at pH 8.3 and 37°C determined the Vmax and Km values of the enzyme to be 714.28 μmol/mg protein/min and 9.09 mM, respectively. The Ki value for acetazolamide was 0.22 mM, compared to 0.099 mM for sulphanilamide. The results from N-terminal amino acid sequencing
imply the purified protein is a putative beta-carbonic anhydrase with close similarities to CAs from plants, microorganisms. 相似文献