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1.
A new method for sequencing linear oligosaccharides on gels using charged, fluorescent conjugates 总被引:3,自引:0,他引:3
A new method is described for sequencing linear oligosaccharides on gels using charged, fluorescent conjugates. The reducing ends of various mono-, di-, tri-, and tetra-saccharides were conjugated with monopotassium 7-amino-1,3-naphthalenedisulfonate (a fluorescent and negatively charged compound) by reductive amination using sodium cyanoborohydride. The sugar conjugates were purified by preparative gradient polyacrylamide gel electrophoresis followed by a newly developed technique involving their semi-dry transfer to positively charged nylon membranes and elution with sodium chloride. The structures of a monosaccharide- and trisaccharide-conjugate were established by f.a.b.-m.s. and 2D n.m.r. Seven linear oligosaccharide-fluorescent conjugates were treated sequentially with exoglycosidases and with endoglycosidases. Analysis of the products by gel electrophoresis provided sequence information. These methods may be useful for sequencing oligosaccharides that are chemically or enzymically (endoglycosidase) released from glycoproteins, glycolipids, and proteoglycans. 相似文献
2.
Inamul Hasan Madar Ghazala Sultan Iftikhar Aslam Tayubi Atif Noorul Hasan Bandana Pahi Anjali Rai Pravitha Kasu Sivanandan Tamizhini Loganathan Mahamuda Begum Sneha Rai 《Bioinformation》2021,17(2):348
Alzheimer''s Disease (AD) is one of the most common causes of dementia, mostly affecting the elderly population. Currently, there is no proper diagnostic tool or method available for the detection of AD. The present study used two distinct data sets of AD genes, which could be potential biomarkers in the diagnosis. The differentially expressed genes (DEGs) curated from both datasets were used for machine learning classification, tissue expression annotation and co-expression analysis. Further, CNPY3, GPR84, HIST1H2AB, HIST1H2AE, IFNAR1, LMO3, MYO18A, N4BP2L1, PML, SLC4A4, ST8SIA4, TLE1 and N4BP2L1 were identified as highly significant DEGs and exhibited co-expression with other query genes. Moreover, a tissue expression study found that these genes are also expressed in the brain tissue. In addition to the earlier studies for marker gene identification, we have considered a different set of machine learning classifiers to improve the accuracy rate from the analysis. Amongst all the six classification algorithms, J48 emerged as the best classifier, which could be used for differentiating healthy and diseased samples. SMO/SVM and Logit Boost further followed J48 to achieve the classification accuracy. 相似文献
3.
Equilibrium tautomeric mixtures of several mono- and disaccharides are obtained in anhydrous form, without the use of water, by reacting the commercially available reducing sugars with ammonia gas in dry methanol, followed by the concentration of the resultant solution to dryness. Mutarotation and hydrolysis of the initially formed glycosylamine in the resultant medium account for the transformation. Equilibrium anomeric mixtures enriched in the beta-form of commercially available sugars such as alpha-D-glucose and alpha-lactose have not only vastly increased solubility, but are also synthetically valuable as these can be readily converted to the methyl/benzyl/trimethylsilyl ether and other derivatives for further transformations. 相似文献
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5.
Galactonate determination in urine by stable isotope dilution gas chromatography-mass spectrometry 总被引:1,自引:0,他引:1
Schadewaldt P Hammen HW Stolpmann S Kamalanathan L Wendel U 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2004,801(2):249-255
A stable isotope dilution assay was developed for the sensitive determination of D-galactonic acid. D-[U-13C(6)]galactono-1,4-lactone was prepared as internal standard. Unlabelled and U-13C-labelled D-galactonic acid species were converted to the N-(1-butyl)galactonamide pentaacetate derivatives and assessed by gas chromatography-mass spectrometry (GC-MS). Positive chemical ionisation and monitoring of the [MH-60](+)-ions in the galactonate chromatographic peak at m/z 402 and m/z 408 were used for quantification. The procedure was applied to study the variability of D-galactonate excretion in healthy subjects and galactosemic patients and to monitor the D-galactonate-D-galactitol ratio in human urine. 相似文献
6.
Rhizobia are used exclusively in agricultural systems for enhancing the ability of legumes to fix atmospheric nitrogen. Knowledge about the indigenous population is necessary for the selection and application of inoculant strains. In this study, we have assessed the genetic diversity of Bradyrhizobium strains isolated from the host plant, Arachis hypogaea along the coastline of Tamil Nadu. Different populations collected from varying environmental conditions were analysed for salt and pH tolerance. Genetic diversity among the strains was studied using RAPD markers and PCR-RFLP of 16S rDNA and nifD genes. The approaches used in this study yielded consistent results, which revealed a high degree of heterogeneity among strains and detection of two distinct genetic groups. 相似文献
7.
Murugan Loganathan Subbiyan Maruthasalam Ling Yin Shiu Wei Ching Lien Wen Hwei Hsu Pei Fang Lee Chih Wen Yu Chin Ho Lin 《In vitro cellular & developmental biology. Plant》2010,46(3):265-273
We describe here a simple and efficient system of soybean (Glycine max L. Merrill) regeneration through direct somatic embryogenesis by using immature embryonic shoot tips (IEST) as explants.
The cultivar Kaohsiung 10 (cv. K10) used in this study did not show embryogenic response either from mature seed-derived explants
(cotyledon, embryonic tip, leaf, shoot and root) or immature cotyledons. However, it showed a high percentage (55.8%) of somatic
embryo (SEm) formation from the IEST excised 2–3 wk after flowering, thus indicating the crucial roles of type and age of
explants. The IEST put forth primary SEm after 2 mo of culturing on Murashige and Skoog (MS) medium supplemented with 6% sucrose,
164.8 μM 2,4-dichlorophenoxyacetic acid (2,4-D), 5 mM asparagine and 684 μM glutamine. Subsequently, secondary SEm were developed
1 mo after culturing on MS medium containing 123.6 μM 2,4-D and 3% sucrose. Cotyledonary embryos were induced on MS medium
supplemented with 0.5% activated charcoal after 1 mo. The embryos were desiccated for 72–96 h on sterile Petri dishes and
regenerated on hormone-free MS medium. Plantlets with well-developed shoots and roots were obtained within 5–6 mo of culturing
of IEST. The SEm-derived plants were morphologically normal and fertile. Various parameters thought to be responsible for
efficient regeneration of soybean through somatic embryogenesis are discussed. To our knowledge, this is the first report
to employ IEST as explants for successful direct somatic embryogenesis in soybean. 相似文献
8.
Loganathan Ponnusamy Dawn M. Wesson Consuelo Arellano Coby Schal Charles S. Apperson 《Microbial ecology》2010,59(1):158-173
In the container habitats of immature mosquitoes, catabolism of plant matter and other organic detritus by microbial organisms
produces metabolites that mediate the oviposition behavior of Aedes aegypti and Aedes albopictus. Public health agencies commonly use oviposition traps containing plant infusions for monitoring populations of these mosquito
species, which are global vectors of dengue viruses. In laboratory experiments, gravid females exhibited significantly diminished
responses to experimental infusions made with sterilized white oak leaves, showing that attractive odorants were produced
through microbial metabolic activity. We evaluated effects of infusion concentration and fermentation time on attraction of
gravid females to infusions made from senescent bamboo or white oak leaves. We used plate counts of heterotrophic bacteria,
total counts of 4′,6-diamidino-2-phenylindole-stained bacterial cells, and 16S ribosomal DNA (rDNA) polymerase chain reaction–denaturing
gradient gel electrophoresis (DGGE) to show that changes in the relative abundance of bacteria and the species composition
of bacterial communities influenced attraction of gravid A. aegypti and A. albopictus mosquitoes to infusions. DGGE profiles showed that bacterial species composition in infusions changed over time. Principal
components analysis indicated that oviposition responses to plant infusions were in general most affected by bacterial diversity
and abundance. Analysis of bacterial 16S rDNA sequences derived from DGGE bands revealed that Proteobacteria (Alpha-, Beta-,
Delta-, and Gamma-) were the predominant bacteria detected in both types of plant infusions. Gravid A. aegypti were significantly attracted to a mix of 14 bacterial species cultured from bamboo leaf infusion. The oviposition response
of gravid mosquitoes to plant infusions is strongly influenced by abundance and diversity of bacterial species, which in turn
is affected by plant species, leaf biomass, and fermentation time. 相似文献
9.
Subbiyan Maruthasalam Ling Yin Shiu Murugan Loganathan Wei Ching Lien Yi Lun Liu Ching Mei Sun Chih Wen Yu Shu Hsien Hung Yeong Ko Chin Ho Lin 《Plant Growth Regulation》2010,60(2):83-90
Ethylene, a gaseous plant hormone, is responsible for the initiation of reproductive development in pineapple. Reproductive
development can be forced in pineapple (Ananas comosus var. comosus) throughout the year with ethylene. Inhibition of natural flowering initiation with aviglycine [(S)-trans-2-amino-4-(2-aminoethoxy)-3-butenoic acid hydrochloride], an inhibitor of ethylene biosynthesis, provides evidence
that reproductive development in response to cold stress and short daylength is also in response to ethylene production. We
studied the effect of cold treatment of pineapple on ethylene production and flower induction by applying a short-term cold
stress to stem apices. Shoot apices of pineapple treated with ice crystals also produced twice as much ethylene as did those
of control plants and significantly more than was produced by “D” leaf basal tissue. Moreover, pineapple plants treated four
times with ice crystals or ice water were induced to flower under field conditions and the forcing efficiency, as evaluated
by the percentages of inflorescence emergence and fruit harvest, was comparable to forcing with calcium carbide (CaC2) and ethephon. In another field experiment two applications of a 1.0% solution of CaC2 or 0.15% ethephon applied at 48 h intervals was sufficient to force reproductive development of ‘Tainon 17’. Furthermore,
0.5 or 1.0% solutions of CaC2 supplemented with 0.5% activated charcoal (AC) significantly improved the forcing effectiveness of CaC2. This could/would make it possible to reduce the number or concentration, or both, of CaC2 required to effect forcing in pineapple. 相似文献
10.
Synthesis,Molecular Structure,and Chiroptical Properties of Dibenzylidene Derivatives of Bicyclo[3.3.1]nonane and Brexane 下载免费PDF全文
Synthesis of several enantiomerically pure unsaturated bicyclo[3.3.1]nonane and related brexane (tricyclo[4.3.0.03,7]nonane) derivatives bearing exocyclic benzylidene substituents from readily available (+)‐(1S,5S)‐bicyclo[3.3.1]nonane‐2,6‐dione was accomplished. Molecular geometry and chiroptical properties of compounds with enone and styrene chromophores were studied by X‐ray diffraction analysis, molecular modeling, and circular dichroism (CD) spectroscopy. Difunctional 3,7‐dibenzylidenebicyclo[3.3.1]nonanes, such as 2 and 7 , 8 , 9 , exhibited intense CD couplets, arising from the exciton coupling between the two unsaturated chromophores. The observed negative sign of the exciton couplets is congruent with the negative twist (negative chirality) defined by the two interacting transition dipoles. The sign of the Cotton effect corresponding to the π→π* transitions in the CD spectra of monoenone 4 and tricyclic brexane acetate 11 was correlated with the intrinsic dissymmetry (helicity) of the styrene chromophore. Chirality 27:728–737, 2015. © 2015 Wiley Periodicals, Inc. 相似文献