A magnetic nanoprobe technology for detecting molecular interactions in live cells     

Won J  Kim M  Yi YW  Kim YH  Jung N  Kim TK 《Science (New York, N.Y.)》2005,309(5731):121-125

Technologies to assess the molecular targets of biomolecules in living cells are lacking. We have developed a technology called magnetism-based interaction capture (MAGIC) that identifies molecular targets on the basis of induced movement of superparamagnetic nanoparticles inside living cells. Efficient intracellular uptake of superparamagnetic nanoparticles (coated with a small molecule of interest) was mediated by a transducible fusogenic peptide. These nanoprobes captured the small molecule's labeled target protein and were translocated in a direction specified by the magnetic field. Use of MAGIC in genome-wide expression screening identified multiple protein targets of a drug. MAGIC was also used to monitor signal-dependent modification and multiple interactions of proteins.  相似文献   

The anatomy of the world's largest extinct rodent     

Sánchez-Villagra MR  Aguilera O  Horovitz I 《Science (New York, N.Y.)》2003,301(5640):1708-1710

Phoberomys is reported to be the largest rodent that ever existed, although it has been known only from isolated teeth and fragmentary postcranial bones. An exceptionally complete skeleton of Phoberomys pattersoni was discovered in a rich locality of fossil vertebrates in the Upper Miocene of Venezuela. Reliable body mass estimates yield approximately 700 kilograms, more than 10 times the mass of the largest living rodent, the capybara. With Phoberomys, Rodentia becomes one of the mammalian orders with the largest size range, second only to diprotodontian marsupials. Several postcranial features support an evolutionary relationship of Phoberomys with pakaranas from the South American rodent radiation. The associated fossil fauna is diverse and suggests that Phoberomys lived in marginal lagoons and wetlands.  相似文献   

Early origin and recent expansion of Plasmodium falciparum     

Joy DA  Feng X  Mu J  Furuya T  Chotivanich K  Krettli AU  Ho M  Wang A  White NJ  Suh E  Beerli P  Su XZ 《Science (New York, N.Y.)》2003,300(5617):318-321

The emergence of virulent Plasmodium falciparum in Africa within the past 6000 years as a result of a cascade of changes in human behavior and mosquito transmission has recently been hypothesized. Here, we provide genetic evidence for a sudden increase in the African malaria parasite population about 10,000 years ago, followed by migration to other regions on the basis of variation in 100 worldwide mitochondrial DNA sequences. However, both the world and some regional populations appear to be older (50,000 to 100,000 years old), suggesting an earlier wave of migration out of Africa, perhaps during the Pleistocene migration of human beings.  相似文献   

Antihyperlipidemic and body fat-lowering effects of silk proteins with different fibroin/sericin compositions in mice fed with high fat diet     

Seo CW  Um IC  Rico CW  Kang MY 《Journal of agricultural and food chemistry》2011,59(8):4192-4197

The effect of silk protein with different fibroin/sericin compositions on body weight and lipid metabolism in high fat-fed mice was investigated. The animals were given experimental diets for 6 weeks: normal control (NC), high fat (HF) and high fat diet supplemented with F100 (pure fibroin, HF-F100), F81 (81:19 fibroin/sericin, w/w, HF-F81) or F50 (50:50 fibroin/sericin, w/w, HF-F50). The silk protein-fed mice showed markedly reduced body weight and enhanced lipid profile relative to the HF group. In general, the amount of body fat, triglyceride and total plasma cholesterol levels, atherogenic index and free fatty acid level tended to decrease, while the HDL-cholesterol level increased, with increased amount of sericin in the diet. This hypolipidemic effect was partly due to increased fecal lipid excretion, inhibition of lipogenesis and regulation of adipokine production. These findings illustrate that silk protein, particularly sericin, may be beneficial in the prevention of high fat diet-induced hyperlipidemia and obesity.  相似文献   

Supercritical carbon dioxide micronization of zeaxanthin from moderately thermophilic bacteria Muricauda lutaonensis CC-HSB-11T     

Hameed A  Arun AB  Ho HP  Chang CM  Rekha PD  Lee MR  Singh S  Young CC 《Journal of agricultural and food chemistry》2011,59(8):4119-4124

Moderately thermophilic bacterial strain CC-HSB-11(T) (Muricauda lutaonensis), which was described recently from a coastal hot spring of Green Island, Taiwan, has been identified to produce zeaxanthin as a predominant xanthophyll by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Cell culture in bioreactor produced 3.12 ± 0.18 mg zeaxanthin L(-1) of culture. Micronization of zeaxanthin was achieved through supercritical carbon dioxide antisolvent precipitation method. Yield of zeaxanthin after the process was 53.4%. Dynamic light scattering assay determined the polydisperse existence of micronized particles of size 3 nm to 2 μm. Field emission scanning electron microscopy revealed distinct morphology and size distribution heterogeneity of particles. Integrity of zeaxanthin after the antisolvent process was assessed by LC-MS/MS. The technique capitalizes on the inherent ability of CC-HSB-11(T) to synthesize zeaxanthin and the work demonstrated feasibility of antisolvent precipitation method to produce microparticles exploiting a bacterial strain.  相似文献   

Apple polyphenols extend the mean lifespan of Drosophila melanogaster     

Peng C  Chan HY  Huang Y  Yu H  Chen ZY 《Journal of agricultural and food chemistry》2011,59(5):2097-2106

Apple polyphenols (AP) are an excellent source of dietary antioxidants. The present study investigated the effect of AP on the lifespan of fruit flies and their interaction with gene expressions of superoxide dismutase (SOD), catalase (CAT), methuselah (MTH), Rpn11, and cytochrome c oxidase (CcO) subunits III and VIb. Results showed the mean lifespan was significantly extended by 10% in fruit flies fed the AP diet. This was accompanied by up-regulation of genes SOD1, SOD2, and CAT and down-regulation of MTH in the aged fruit flies. Paraquat and H(2)O(2) challenge tests demonstrated that AP prolonged the survival time only for Oregon R wild type flies but not for SOD(n108) or Cat(n1) mutants, in which either SOD or CAT was knocked out. Chronic paraquat exposure could shorten the maximum lifespan from 68 to 31 days and reduce the climbing ability by 60%, whereas AP could partially reverse the paraquat-induced mortality and decline in climbing ability. AP could up-regulate Rpn11 at day 30, whereas it appeared to have no significant effect on gene expression of ubiquitinated protein, CcO subunits III and VIb. These AP-induced changes were unlikely associated with caloric restriction as the gustatory assay found no difference in average body weight and stomach redness index between the control and AP fruit flies. It was therefore concluded that the antiaging activity of AP was, at least in part, mediated by its interaction with genes SOD, CAT, MTH, and Rpn11.  相似文献   

Radical scavenging capacity and antimutagenic properties of purified proteins from Solanum betaceum fruits and Solanum tuberosum tubers     

Ordóñez RM  Zampini IC  Rodríguez F  Cattaneo F  Sayago JE  Isla MI 《Journal of agricultural and food chemistry》2011,59(16):8655-8660

In this study, antioxidant activities in free-radical-mediated oxidative systems and the genotoxic/antigenotoxic effects of two proteins with molecular mass around 17 kDa, purified from Solanum betaceum fruits (cyphomine) and Solanum tuberosum tubers (solamarine), were investigated. Both proteins inhibited uric acid formation with IC(50) values between 55 and 60 μg/mL, and both proteins were able to reduce oxidative damage by scavenging hydroxyl radicals and superoxide anion in a dose-dependent manner. Furthermore, the DPPH? reduction assay showed SC(50) values of 55-73 μg/mL. Cyphomine and solamarine were able to retain their antioxidant activity after heat treatment at 80 °C for 15 min. Allium cepa and Salmonella /microsome assays showed no genotoxic and mutagenic effects. Solamarine showed an antimutagenic effect against a direct mutagen (4-nitro-o-phenylenediamine). Consequently, the present study showed that the investigated proteins are promising ingredients for the development of functional foods with a beneficial impact on human health and an important source for the production of bioactive peptides.  相似文献   

Molecular characterization of tetracycline- and quinolone-resistant Aeromonas salmonicida isolated in Korea     

Ji Hyung Kim  Sun Young Hwang  Jee Soo Son  Jee Eun Han  Jin Woo Jun  Sang Phil Shin  Casiano Choresca  Jr  Yun Jaie Choi  Yong Ho Park  Se Chang Park 《Journal of veterinary science (Suw?n-si, Korea)》2011,12(1):41-48

The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolates harbored tetA gene and one isolate harbored tetE gene. Additionally, quinolone-resistance determining regions (QRDRs) consisting of the gyrA and parC genes were amplified and sequenced. Among the quinolone-resistant A. salmonicida strains, 15 harbored point mutations in the gyrA codon 83 which were responsible for the corresponding amino acid substitutions of Ser⁸³→Arg⁸³ or Ser⁸³→Asn⁸³. We detected no point mutations in other QRDRs, such as gyrA codons 87 and 92, and parC codons 80 and 84. Genetic similarity was assessed via pulsed-field gel electrophoresis, and the results indicated high clonality among the Korean antibiotic-resistant strains of A. salmonicida.  相似文献   

Efficacy of probiotics from anaerobic microflora with prebiotics on growth performance and noxious gas emission in growing pigs     

Ho Sik JEONG  Sung Sill LEE 《Animal Science Journal》2011,82(2):282-290

We investigated the effect of probiotics from anaerobic microflora with prebiotics (synbiotics) on growth performance, noxious gas emission and fecal pathogenic bacteria populations in growing pigs. The basal diet, which contained approximately 25% corn, 24% whey, 12% wheat and 12% soybean meal, was supplemented alternatively with 0.15% antibiotics (US diet), prebiotics and 0.2% probiotics from anaerobic bacteria (BS diet), yeast (YS diet), mold (MS diet) or compounds (CS diet). One hundred and fifty pigs were fed an experimental diet for 15 days. Although the growth performance was not affected by supplemental synbiotics, the BS group showed higher dry matter and crude protein digestibility. The BS group decreased fecal ammonia and amine gas emissions, and increased fecal acetate gas emission compared with the US group. All synbiotics groups decreased in fecal propionate gas emission. Fecal Escherichia coli population was lower in the synbiotics groups than in the US group. Therefore, the results of the present study suggest that synbiotics exert similar effects with antibiotics on the nutrient digestibility and fecal microflora composition in growing pigs. Moreover, synbiotics can also decrease the fecal noxious gas emission in growing pigs.  相似文献   

Analysis of methanogenic archaeal communities of rumen fluid and rumen particles from Korean black goats     

Min‐Jung GU  Md. Jahangir ALAM  Seon‐Ho KIM  Che‐Ok JEON  Moon‐Baek CHANG  Young‐Kyoon OH  Sang‐Cheol LEE  Sang‐Suk LEE 《Animal Science Journal》2011,82(5):663-672

Molecular diversity of methanogens in the rumen of Korean black goats was investigated with 16S rRNA gene clone libraries using methanogen‐specific primers. The libraries were composed of rumen fluid‐associated methanogens (FAM) and rumen particle‐associated methanogens (PAM) from rumen‐fistulated Korean black goats. Among the 141 clones of the FAM library, the sequences were mostly related to two phyla, the Methanobacteriaceae family (77.3%) and the Thermoplasmatales family (22.7%); and among the 68 clones of the PAM library, sequences were also mainly clustered in the two phyla, the Thermoplasmatales family (63.24%) and the Methanobacteriaceae family (35.29%). Most of the sequenced clones in the two libraries were closely related to uncultured methanogenic archaeon. Quantitative real‐time PCR revealed that PAM (8.97 log 10) had significantly higher (P < 0.01) density of methanogens by the methanogenic 16S rRNA gene copies than FAM (7.57 log 10). The two clone libraries also showed difference in Shannon index (FAM library 1.70 and PAM library 1.59) and Chao 1 estimator (FAM library 18 and PAM library 17 operational taxonomic units). Apparent differences found in the microbial community from the two 16S rRNA gene libraries could be a result of such factors as the chemical and physical nature of the target material surface, types or component of diets, the interaction between the methanogens and other microbes, and age of the experimental goats.  相似文献