三聚体纳米颗粒自组装过程的分子动力学模拟     

冯涛  王珂  周进杰  Deepak Bhopatkar  陈枫  Osvaldo Campanell  Bruce R. Hamaker  Marcelo Carignano  庄海宁 《农业工程学报》2017,33(3):300-306

为了更深入理解直链淀粉/β-乳球蛋白/α-亚油酸三元复合物体系自组装行为的机制,该研究借助Gromacs软件,采用分子动力学模拟对玉米直链淀粉、β-乳球蛋白、α-亚油酸三者在373 K温度下的结合过程进行研究。通过三元纳米粒子在500 ns内的自组装快照图,可以得出直链淀粉、α-亚油酸、β-乳球蛋白3种组分的结合顺序。通过三元纳米粒子的自由能曲面图,可知该三元纳米粒子的形成是热力学自发的过程。进一步对其水合半径及溶剂可接触表面积的分析表明,该三元复合物纳米颗粒溶解性良好。研究阐释了水溶性自组装纳米颗粒的形成机理,为纳米科学领域寻找合适的壁材提供了一种新的研究途径。  相似文献   

Inhibition of Iron Induced Lipid Peroxidation and Antioxidant Activity of Indian Spices and Acacia In Vitro     

Amit Singh Yadav  Deepak Bhatnagar 《Plant foods for human nutrition (Dordrecht, Netherlands)》2010,65(1):18-24

The spices used in the Indian foods such as Star anise (Illicium verum), Bay leaves (Cinnamomum zeylanicum) and Cobra’s saffron (Mesua ferrea), and Acacia (Acacia catechu), which have medicinal value, were used as test samples, to find their effect on in vitro lipid peroxidation (LPO). Rat liver post mitochondrial supernatant (PMS) in Tris HCl buffer, pH 7.4 was incubated for 0 and 1 h, with various test extracts in three different oxidant systems. The results show that addition of test samples to FeCl₃ medium at 0 h significantly stop the initiation of the LPO. However, the propagation phase of LPO was inhibited by Cobra’s saffron and Acacia and not by Star anise and Bay leaves. The test samples also showed strong reducing power and superoxide radical scavenging activity. Cobra’s saffron and Acacia showed the highest antioxidant activity, probably due to the higher polyphenol content as compared to other test samples.  相似文献   

A novel antifungal anthraquinone from seeds of Aegle marmelos Correa (family Rutaceae)     

Bhuwan B. Mishra  Navneet Kishore  Vinod K. Tiwari  Desh D. Singh  Vyasji Tripathi 《Fitoterapia》2010

A new anthraquinone, 1-methyl-2-(3′-methyl-but-2′-enyloxy)-anthraquinone (1) has been isolated from seeds of Aegle marmelos Correa and was characterized on the basis of spectral analysis (UV, IR, ¹H NMR, ¹³C NMR, 2D NMR and mass spectroscopy). The compound exhibited significant antifungal activity against pathogenic strains of Aspergillus species and Candida albicans in disc diffusion assay (MIC value of 6.25 μg/disc), microbroth dilution and percent spore germination inhibition assays (MIC value of 31.25–62.5 μg/ml).  相似文献   

A high-throughput method for isolation of salicylic acid metabolic mutants     

George Marek  Ryan Carver  Yezhang Ding  Deepak Sathyanarayan  Xudong Zhang  Zhonglin Mou 《Plant methods》2010,6(1):21

Background  

Salicylic acid (SA) is a key defense signal molecule against biotrophic pathogens in plants. Quantification of SA levels in plants is critical for dissecting the SA-mediated immune response. Although HPLC and GC/MS are routinely used to determine SA concentrations, they are expensive and time-consuming. We recently described a rapid method for a bacterial biosensor Acinetobacter sp. ADPWH_lux-based SA quantification, which enables high-throughput analysis. In this study we describe an improved method for fast sample preparation, and present a high-throughput strategy for isolation of SA metabolic mutants.  相似文献   

Influence of dietary phosphorus on mineralization and morphology of Indian major carp,catla (<Emphasis Type="Italic">Catla catla</Emphasis>) fingerlings     

Krishna Sukumaran  Asim K. Pal  Narottam P. Sahu  Shrinivas Jahageerdar  Deepak Khambadakone  Dipesh Debnath 《Aquaculture International》2011,19(4):749-763

The present study was conducted to investigate the changes in mineralization and morphology in response to graded levels of dietary phosphorus in Indian major carp, Catla (Catla catla) fingerlings (av. wt. 4.23 ± 0.87 g). The experimental system constituted of 24 150-L capacity plastic tanks (eight treatments, three replicates) stocked with 20 fingerlings each. Eight isonitrogenous and isocaloric semi-purified diets (crude protein 35%, crude lipid 8.5%) were formulated with graded levels of phosphorus (0%-control; 0.1; 0.3; 0.5; 0.7; 0.9; 1.1; 1.3; 1.5%) using KH₂PO₄. The fish were fed twice daily with the respective feeds for a period of 120 days. The percentage of ash content in whole body, vertebrae and opercular bones was found to be significantly (P < 0.05) lower in fish fed low levels of dietary phosphorus (T₁, T₂) in comparison with other treatments. The concentration of phosphorus and calcium was found to be significantly (P < 0.05) lower in whole body, vertebrae and opercula of fish fed low phosphorus diets (T₁, T₂) relative to treatments with higher levels of dietary phosphorus supplementation. The concentration of magnesium in opercular and vertebral tissues of T₁ group was significantly (P < 0.05) lower than all other groups. The X-ray radiographs did not reveal any skeletal deformities in any of the treatments. Truss analysis showed absence of significant morphological variations between fish of different treatments. The deficiency of dietary phosphorus in catla led to significantly lower mineralization of whole body and bone tissues, but the deficiency was not severe enough to cause skeletal deformities and morphological changes in the fish.  相似文献   

Harnessing mutant donor plants for microspore culture in Indian mustard [Brassica juncea (L.) Czern and Coss]     

Deepak Prem  Kadambari Gupta  Abha Agnihotri 《Euphytica》2012,184(2):207-222

Haploid mutagenesis offers several advantages over conventional (seed) approach. However, its potential has not been utilised for Brassica juncea, an important oilseed. In this study, mutant donor plants of three Indian B. juncea genotypes, generated by ethyl methanesulfonate (EMS) and ethyl nitrosourea (ENU), were used for microspore culture. The response of mutant donor plants was about 100 times lower than non-mutant controls; a total of 9,411 embryos were produced from the EMS treated donor plants, while microspores isolated from ENU treated donors did not yield any embryos. The lethality of induced mutations demonstrated itself mainly as the induction of abnormal embryos (80%), failure of germination (70%) and failure of plantlet development (70%). Nine doubled haploid (DH) mutant lines and three non-mutant DH lines obtained through this approach were tested for agronomic and biochemical variation over two growing seasons. High variability was observed and stable mutants were recovered for reduced height (125 vs. 168 cm for the control), appressed pod character, altered fatty acid composition higher protein proportion in de-oiled meal (48%) and a lower glucosinolate content in de-oiled meal (59.5 μM/g) relative to controls. The approach demonstrates that despite severe reduction in efficiency of the DH line production, valuable mutants can be recovered from mutated donor plants.  相似文献   

Heterosis breeding in Indian mustard (Brassica juncea L. Czern & Coss): Analysis of component characters contributing to heterosis for yield     

Akshay K. Pradhan  Yaspal S. Sodhi  Arundhati Mukhopadhyay  Deepak Pental 《Euphytica》1993,69(3):219-229

Summary Divergence of 25 accessions of Brassica juncea of Indian, CIS (Commonwealth of Independent States, former USSR) and synthetic origin was studied by D² analysis. On the basis of divergence, ten accessions were selected and crossed in a diallel fashion without reciprocals to study the combining ability and heterosis. None of the accessions was found to be a good general combiner for all the nine quantitative characters that were studied. Significant heterosis over better parent for single plant yield was recorded in CIS x Indian and synthetic x CIS crosses (5 each) followed by Indian x synthetic types (3). The analysis of component characters showed that the mean performance of the majority of hybrids was intermediate for five out of six yield attributing traits, thus exhibiting dominance or partial dominance effect. To estimate the contribution of such yield attributing traits towards heterosis for yield, a comparison was made among three parameters viz. heterosis over mid parent (MP), better parent (BP) and better yielding parent (BYP) of the concerned hybrid. It was observed that estimation of heterosis from BYP was a more accurate method to determine the contribution of component characters towards yield heterosis than the analysis based on MP and BP. From the component character analysis, it was concluded that characters like number of primary and secondary branches, number of siliqua per plant and siliqua density contributed significantly towards heterosis in yield. Plot level yield trials of two selected hybrids (Skorospieka II x RH30 and Donskaja IV x Varuna) over two growing seasons revealed 29.4 to 91.8% heterosis over BYP.  相似文献   

Cajanus platycarpus (Benth.) Maesen as the donor of new pigeonpea cytoplasmic male sterile (CMS) system     

Nalini Mallikarjuna  Deepak R. Jadhav  Sandhya Srikanth  Kulbhushan B. Saxena 《Euphytica》2011,182(1):65-71

Cajanus platycarpus, a distantly related wild species, was successfully crossed with cultivated pigeonpea using embryo rescue and tissue culture techniques. Advance generation lines showed a range of desirable characters including cytoplasmic male sterility. A range of pigeonpea cultivars restored fertility and was maintained by a few lines including cultivar ICPL 85010. Clasmogamous flowers were observed in the male sterile lines. In such flowers anthers did not form di-adlephous bundle. Cytological analysis revealed that meiosis proceeded normally till the tetrad stage in those anthers with pollen grains. After which many of the pollen grains turned sterile. In the anthers with pollen grains, dehiscence was not observed, thus creating functional sterility. In many other anthers, pollen mother cells (PMCs) were not formed at all, giving rise to sepalous anthers. In conclusion two mechanisms of male sterility existed, one was premeiotic, where PMCs did not form and in the second, although PMCs gave rise to pollen grains, they were either partially or totally sterile accompanied by non-dehiscence of anther wall.  相似文献   

Rev1 employs a novel mechanism of DNA synthesis using a protein template     

Nair DT  Johnson RE  Prakash L  Prakash S  Aggarwal AK 《Science (New York, N.Y.)》2005,309(5744):2219-2222

The Rev1 DNA polymerase is highly specialized for the incorporation of C opposite template G. We present here the crystal structure of yeast Rev1 bound to template G and incoming 2'-deoxycytidine 5'-triphosphate (dCTP), which reveals that the polymerase itself dictates the identity of the incoming nucleotide, as well as the identity of the templating base. Template G and incoming dCTP do not pair with each other. Instead, the template G is evicted from the DNA helix, and it makes optimal hydrogen bonds with a segment of Rev1. Also, unlike other DNA polymerases, incoming dCTP pairs with an arginine rather than the templating base, which ensures the incorporation of dCTP over other incoming nucleotides. This mechanism provides an elegant means for promoting proficient and error-free synthesis through N2-adducted guanines that obstruct replication.  相似文献   

Detecting maize inoculated with toxigenic and atoxigenic fungal strains with fluorescence hyperspectral imagery     

Haibo Yao  Zuzana Hruska  Russell Kincaid  Robert L. Brown  Deepak Bhatnagar  Thomas E. Cleveland 《Biosystems Engineering》2013,115(2):125-135

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