Use of apple seed meal as a new source of beta-glucosidase for enzymatic glucosylation of 4-substituted benzyl alcohols and tyrosol in monophasic aqueous-dioxane medium

A facile method for enzymatic glycosylation of 4-substituted benzyl alcohols and tyrosol with glucose in a monophasic aqueous-dioxane medium was reported, using a crude meal of apple seed as a new catalyst. The corresponding beta-d-glucosides were synthesized in moderate yields (13.1-23.1%), among which the salidroside was obtained in 15.8% yield.     

Development of Plantlets from Leaf Protoplast Culture in Brassica juncea var. tsatsi

Protoplast of two mustard cultivars: Brassica juncea var. tsatsi cv. “Quxian Jiaoercai” and “Bangbangcai”, were isolated by enzymolysis from leaf grown in vitro. Protoplasts were suspended in liquid medium and semi-solidified medium with 0.35% low melting point agarose which formed a thin layer floating on the surface of the liquid medium. The first division appeared after 48h in the culture. One week after the original culture, a diluted medium with gradual dicrease of mannitol concentrations (6%→4%→zero) was then added to the culture three times respectively at one week's interval. In this culture method cell division and formation of microcalli were achieved. During the liquid culture of protoplasts, shaking at 20 rpm from time to time was beneficial in the formation of cell colonies and microcalli. Cell colonies developed into calli of approx 0.5—1mm in diameter one month after culture. The plating efficiency, which defined as the percentage of microcatli to numbers of protoplasts, was 0.2%—1%. Shoot regeneration occured when leaf protoplast-derived calli of “Quxian Jiaoercai” were transferred onto the modified MS medium supplemented with BAP 2.0mg/L, KT 1.0mg/L and NAA 0.2mg/L, and those of -'Bangbangcai" were transferred onto the modified MS medium supplemented with BAP 2.0mg/L. Individual shoot was rooted on a rooting medium supplemented with NAA 0.2 or 0.4 mg/L.     

Preparative Separation of Enantiomers Based on Functional Nucleic Acids Modified Gold Nanoparticles

The preparative‐scale separation of chiral compounds is vitally important for the pharmaceutical industry and related fields. Herein we report a simple approach for rapid preparative separation of enantiomers using functional nucleic acids modified gold nanoparticles (AuNPs). The separation of _DL‐tryptophan (_DL‐Trp) is demonstrated as an example to show the feasibility of the approach. AuNPs modified with enantioselective aptamers were added into a racemic mixture of _DL‐Trp. The aptamer‐specific enantiomer (_L‐Trp) binds to the AuNPs surface through aptamer‐_L‐Trp interaction. The separation of _DL‐Trp is then simply accomplished by centrifugation: the precipitate containing _L‐Trp bounded AuNPs is separated from the solution, while the _D‐Trp remains in the supernatant. The precipitate is then redispersed in water. The aptamer is denatured under 95 °C and a second centrifugation is then performed, resulting in the separation of AuNPs and _L‐Trp. The supernatant is finally collected to obtain pure _L‐Trp in water. The results show that the racemic mixture of _DL‐Trp is completely separated into _D‐Trp and _L‐Trp, respectively, after 5 rounds of repeated addition of fresh aptamer‐modified AuNPs to the _DL‐Trp mixture solution. Additionally, the aptamer‐modified AuNPs can be repeatedly used for at least eight times without significant loss of its binding ability because the aptamer can be easily denatured and renatured in relatively mild conditions. The proposed approach could be scaled up and extended to the separation of other enantiomers by the adoption of other enantioselective aptamers. Chirality 25:751–756, 2013. © 2013 Wiley Periodicals, Inc.     

SiO2‐Enhanced Structural Stability and Strong Adhesion with a New Binder of Konjac Glucomannan Enables Stable Cycling of Silicon Anodes for Lithium‐Ion Batteries

Silicon‐based anodes with high theoretical capacity have intriguing potential applications for next‐generation high‐energy lithium‐ion batteries, but suffer from huge volumetric change that causes pulverization of electrodes. Rational design and construction of effective electrode structures combined with versatile binders remain a significant challenge. Here, a unique natural binder of konjac glucomannan (KGM) is developed and an amorphous protective layer of SiO₂ is fabricated on the surface of Si nanoparticles (Si@SiO₂) to enhance the adhesion. Benefiting from a plethora of hydroxyl groups, the KGM binder with inherently high adhesion and superior mechanical properties provides abundant contact sites to active materials. Molecular mechanics simulations and experimental results demonstrate that the enhanced adhesion between KGM and Si@SiO₂ can bond the particles tightly to form a robust electrode. In addition to bridging KGM molecules, the SiO₂‐functionalized surface may serve as a buffer layer to alleviate the stresses of Si nanoparticles resulting from the volume change. The as‐fabricated KGM/Si@SiO₂ electrode exhibits outstanding structural stability upon long‐term cycles. A highly reversible capacity of 1278 mAh g^?1 can be achieved over 1000 cycles at a current density of 2 A g^?1, and the capacity decay is as small as 0.056% per cycle.     

Platycodin D Inhibits β-Amyloid-Induced Inflammation and Oxidative Stress in BV-2 Cells Via Suppressing TLR4/NF-κB Signaling Pathway and Activating Nrf2/HO-1 Signaling Pathway

Neurochemical Research - Alzheimer’s disease (AD) is a common neurodegenerative disease associated with deposition of β-amyloid peptide (Aβ). Platycodin D (PLD), a...     

Rapid flip-flop of oleic acid across the plasma membrane of adipocytes

Nonesterified long-chain fatty acids may enter cells by free diffusion or by membrane protein transporters. A requirement for proteins to transport fatty acids across the plasma membrane would imply low partitioning of fatty acids into the membrane lipids, and/or a slower rate of diffusion (flip-flop) through the lipid domains compared to the rates of intracellular metabolism of fatty acids. We used both vesicles of the plasma membrane of adipocytes and intact adipocytes to study transmembrane fluxes of externally added oleic acid at concentrations below its solubility limit at pH 7.4. Binding of oleic acid to the plasma membrane was determined by measuring the fluorescent fatty acid-binding protein ADIFAB added to the external medium. Changes in internal pH caused by flip-flop and metabolism were measured by trapping a fluorescent pH indicator in the cells. The metabolic end products of oleic acid were evaluated over the time interval required for the return of intracellular pH to its initial value. The primary findings were that (i) oleic acid rapidly binds with high avidity in the lipid domains of the plasma membrane with an apparent partition coefficient similar to that of protein-free phospholipid bilayers; (ii) oleic acid rapidly crosses the plasma membrane by the flip-flop mechanism (both events occur within 5 s); and (iii) the kinetics of esterification of oleic acid closely follow the time dependence of the recovery of intracellular pH. Any postulated transport mechanism for facilitating translocation of fatty acid across the plasma membrane of adipocytes, including a protein transporter, would have to compete with the highly effective flip-flop mechanism.     

A recombinant anti-erbB2, scFv-Fc-IL-2 fusion protein retains antigen specificity and cytokine function

Elevated erbB2 expression is detected in many in situ and invasive human ductal carcinomas. Anti-erbB2 antibody directed at the extracellular domain of erbB2 can result in an antitumor response in some patients with tumors overexpressing erbB2 oncoprotein. By combining interleukin 2 (IL-2) activities with a tumor specific antibody, immunotherapy of tumors might be more effective in the future. In this study, a fusion protein consisting of erbB2 single chain antibody (scFv), Fc fragment of human IgG1 and IL-2 was constructed. The molecular weight of fusion proteins is 66 kDa, only one third of whole antibody-IL-2 fusion protein or 44% whole Ig molecule. The fusion proteins retained the activities of both antigen binding and IL-2. The scFv-Fc-IL-2 fusion protein may have advantages over whole antibody-IL-2 fusion proteins, such as smaller molecule, better activity of penetration, more favorable pharmacokinetic properties.     

An integrated genetic linkage map of cultivated peanut (Arachis hypogaea L.) constructed from two RIL populations

Construction and improvement of a genetic map for peanut (Arachis hypogaea L.) continues to be an important task in order to facilitate quantitative trait locus (QTL) analysis and the development of tools for marker-assisted breeding. The objective of this study was to develop a comparative integrated map from two cultivated × cultivated recombinant inbred line (RIL) mapping populations and to apply in mapping Tomato spotted wilt virus (TSWV) resistance trait in peanut. A total of 4,576 simple sequence repeat (SSR) markers from three sources: published SSR markers, newly developed SSR markers from expressed sequence tags (EST) and from bacterial artificial chromosome end-sequences were used for screening polymorphisms. Two cleaved amplified polymorphic sequence markers were also included to differentiate ahFAD2A alleles and ahFAD2B alleles. A total of 324 markers were anchored on this integrated map covering 1,352.1 cM with 21 linkage groups (LGs). Combining information from duplicated loci between LGs and comparing with published diploid maps, seven homoeologous groups were defined and 17 LGs (A1-A10, B1-B4, B7, B8, and B9) were aligned to corresponding A-subgenome or B-subgenome of diploid progenitors. One reciprocal translocation was confirmed in the tetraploid-cultivated peanut genome. Several chromosomal rearrangements were observed by comparing with published cultivated peanut maps. High consistency with cultivated peanut maps derived from different populations may support this integrated map as a reliable reference map for peanut whole genome sequencing assembling. Further two major QTLs for TSWV resistance were identified for each RILs, which illustrated the application of this map.     

Mitochondrial cytochrome b Sequence Variation and Phylogenetics of the Highly Specialized Schizothoracine Fishes (Teleostei: Cyprinidae) in the Qinghai-Tibet Plateau

The complete 1140 bp mitochondrial cytochrome b sequences were obtained from 39 individuals representing five species of all four genera of highly specialized schizothoracine fishes distributed in the Qinghai-Tibet plateau. Sequence variation of the cytochrome b gene was surveyed among the 39 individuals as well as three primitive schizothoracines and one outgroup. Phylogenetic analysis suggested that the group assignment based on 1140 bp of the cytochrome b sequence is obviously different from previous assignments, and the highly specialized schizothoracine fishes (Schizopygopsis pylzovi, Gymnocypris przewalskii, G. eckloni, Chuanchia labiosa, and Platypharodon extremus) form a monophyletic group that is sister to the clade formed by the primitive schizothoracine fishes (Schizothorax prenanti, S. pseudaksaiensis, and S. argentatus). The haplotypes of Schizopygopsis pylzovi and G. przewalskii were paraphyletic based on cytochrome b data, which most likely reflected incomplete sorting of mitochondrial DNA lineages. The diploid chromosome numbers of Schizothoracinae were considered in phylogenetic analysis and provided a clear pattern of relationships. Molecular dating estimated for highly specialized schizothoracine fishes suggested that the highly specialized schizothoracine fishes diverged in the late Miocene Pliocene to Pleistocene (4.5 × 10⁴–4.05 × 10⁶ years BP). The relationship between the cladogenesis of highly specialized schizothoracine fishes and geographical events of the Qinghai-Tibet plateau is discussed.     

Detecting complexes from edge-weighted PPI networks via genes expression analysis

Background

Identifying complexes from PPI networks has become a key problem to elucidate protein functions and identify signal and biological processes in a cell. Proteins binding as complexes are important roles of life activity. Accurate determination of complexes in PPI networks is crucial for understanding principles of cellular organization.

Results

We propose a novel method to identify complexes on PPI networks, based on different co-expression information. First, we use Markov Cluster Algorithm with an edge-weighting scheme to calculate complexes on PPI networks. Then, we propose some significant features, such as graph information and gene expression analysis, to filter and modify complexes predicted by Markov Cluster Algorithm. To evaluate our method, we test on two experimental yeast PPI networks.

Conclusions

On DIP network, our method has Precision and F-Measure values of 0.6004 and 0.5528. On MIPS network, our method has F-Measure and S _n values of 0.3774 and 0.3453. Comparing to existing methods, our method improves Precision value by at least 0.1752, F-Measure value by at least 0.0448, S _n value by at least 0.0771. Experiments show that our method achieves better results than some state-of-the-art methods for identifying complexes on PPI networks, with the prediction quality improved in terms of evaluation criteria.