Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Language
Year
Topic
  • 1
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 20 December 2011, Vol.108(51), pp.20325-32
    Description: Telomerase is a unique reverse transcriptase that catalyzes the addition of telomere DNA repeats onto the 3' ends of linear chromosomes and plays a critical role in maintaining genome stability. Unlike other reverse transcriptases, telomerase is unique in that it is a ribonucleoprotein complex, where the RNA component [telomerase RNA (TR)] not only provides the template for the synthesis of telomere DNA repeats but also plays essential roles in catalysis, accumulation, TR 3'-end processing, localization, and holoenzyme assembly. Biochemical studies have identified TR elements essential for catalysis that share remarkably conserved secondary structures across different species as well as species-specific domains for other functions, paving the way for high-resolution structure determination of TRs. Over the past decade, structures of key elements from the core, conserved regions 4 and 5, and small Cajal body specific RNA domains of human TR have emerged, providing significant insights into the roles of these RNA elements in telomerase function. Structures of all helical elements of the core domain have been recently reported, providing the basis for a high-resolution model of the complete core domain. We review this progress to determine the overall architecture of human telomerase RNA.
    Keywords: RNA -- Genetics ; Telomerase -- Genetics
    ISSN: 00278424
    E-ISSN: 1091-6490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Journal of the American Chemical Society, 30 October 2013, Vol.135(43), pp.16213-9
    Description: Molecular capsules have attracted interest as simple enzyme mimetics and several examples of catalytic transformations in water-soluble metal-ligand based systems have been reported. This is not the case for hydrogen-bond based molecular capsules, which in contrast can be employed in organic solvents. We describe herein our investigations of such a system: The resorcin[4]arene hexamer is one of the largest hydrogen bond-based self-assembled capsules and has been studied intensively due to its ready availability. We present evidence that the capsule acts as a reasonably strong Brønsted acid (pKa approximately 5.5-6). This finding explains the capsule's high affinity toward tertiary amines that are protonated and therefore encounter cation-π interactions inside the cavity. We were able to translate this finding into a first synthetic application: A highly substrate-selective Wittig reaction. We also report that this property renders the capsule an efficient enzyme-like catalyst for substrate selective diethyl acetal hydrolysis.
    Keywords: Calixarenes -- Chemistry ; Phenylalanine -- Analogs & Derivatives
    ISSN: 00027863
    E-ISSN: 1520-5126
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Journal of Chromatography A, Sept 6, 2013, Vol.1306, p.97(7)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.chroma.2013.07.053 Byline: Qi Zhang, Yingxiang Du Abstract: acents Polysaccharides-based chiral ILs synergistic systems were first established. acents Two novel amino acid ILs were applied for the first time in CE enantioseparation. acents A central composite design was carried out to optimize the synergistic systems. acents Excellent enantiosepations were achieved for all selected drug enantiomers. Author Affiliation: (a) Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009, PR China (b) Key Laboratory of Drug Quality Control and Pharmacovigilance (Ministry of Education), China Pharmaceutical University, Nanjing 210009, PR China (c) State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, PR China Article History: Received 22 February 2013; Revised 14 July 2013; Accepted 15 July 2013
    Keywords: Amino Acids -- Analysis ; Enantiomers -- Analysis ; Glucose Metabolism -- Analysis ; Glycogen -- Analysis
    ISSN: 0021-9673
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 06 November 2012, Vol.109(45), pp.18361-6
    Description: Lanthionine-containing peptides (lanthipeptides) are a family of ribosomally synthesized and posttranslationally modified peptides containing (methyl)lanthionine residues. Here we present a phylogenomic study of the four currently known classes of lanthipeptide synthetases (LanB and LanC for class I, LanM for class II, LanKC for class III, and LanL for class IV). Although they possess very similar cyclase domains, class II-IV synthetases have evolved independently, and LanB and LanC enzymes appear to not always have coevolved. LanM enzymes from various phyla that have three cysteines ligated to a zinc ion (as opposed to the more common Cys-Cys-His ligand set) cluster together. Most importantly, the phylogenomic data suggest that for some scaffolds, the ring topology of the final lanthipeptides may be determined in part by the sequence of the precursor peptides and not just by the biosynthetic enzymes. This notion was supported by studies with two chimeric peptides, suggesting that the nisin and prochlorosin biosynthetic enzymes can produce the correct ring topologies of epilancin 15X and lacticin 481, respectively. These results highlight the potential of lanthipeptide synthetases for bioengineering and combinatorial biosynthesis. Our study also demonstrates unexplored areas of sequence space that may be fruitful for genome mining.
    Keywords: Evolution, Molecular ; Ligases -- Genetics ; Peptides -- Metabolism
    ISSN: 00278424
    E-ISSN: 1091-6490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Journal of the American Chemical Society, 08 January 2014, Vol.136(1), pp.20-3
    Description: Quantitative characterization of dynamic exchange between various conformational states provides essential insights into the molecular basis of many regulatory RNA functions. Here, we present an application of nucleic-acid-optimized carbon chemical exchange saturation transfer (CEST) and low spin-lock field R(1ρ) relaxation dispersion (RD) NMR experiments in characterizing slow chemical exchange in nucleic acids that is otherwise difficult if not impossible to be quantified by the ZZ-exchange NMR experiment. We demonstrated the application on a 47-nucleotide fluoride riboswitch in the ligand-free state, for which CEST and R(1ρ) RD profiles of base and sugar carbons revealed slow exchange dynamics involving a sparsely populated (p ~ 10%) and shortly lived (τ ~ 10 ms) NMR "invisible" state. The utility of CEST and low spin-lock field R(1ρ) RD experiments in studying slow exchange was further validated in characterizing an exchange as slow as ~60 s(-1).
    Keywords: Magnetic Resonance Spectroscopy ; Carbon -- Chemistry ; Nucleic Acids -- Chemistry
    ISSN: 00027863
    E-ISSN: 1520-5126
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: Biophysical Journal, 03 February 2017, Vol.112(3), pp.394a-394a
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.bpj.2016.11.2139 Byline: Qi Zhang Author Affiliation: Pharmacology, Vanderbilt University, Nashville, TN, USA Article Note: (miscellaneous) 1946-PosB266
    Keywords: Biology
    ISSN: 0006-3495
    E-ISSN: 1542-0086
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Journal of Colloid And Interface Science, 01 April 2012, Vol.371(1), pp.73-81
    Description: ► The headgroup alkyl chain affects the thermodynamic properties of gemini surfactants. ► The temperature of the minimum of cmc ( ) increases with increasing the headgroup alkyl chain length. ► Log (cmc) does not vary linearly with carbon number of the headgroup alkyl chain. ► The enthalpy–entropy compensation plots exhibit excellent linearity. A series of cationic gemini surfactants butanediyl-1,4-bis(dodecyldialkylammonium bromide), C H N (C H ) C H N (C H ) C H ·2Br , where = 1, 2, 3, 4, referred to as C C C (Me), C C C (Et), C C C (Pr), and C C C (Bu), respectively, were synthesized, and their thermodynamic properties of micellization were studied by electrical conductivity measurements. There existed a minimum critical micelle concentration (cmc) in the curve of cmc versus temperature, and the temperature of the minimum of cmc ( ) increased with increasing the headgroup alkyl chain length. The values of log (cmc) depended linearly on carbon number of the alkyl chains, but that was not true for the carbon number of the headgroup substituents. The temperature dependence of cmc and degree of counterion association ( ) were used to calculate the Gibbs free energy (Δ °), enthalpies (Δ °) and entropies (Δ °) of micelle formation for these gemini surfactants, and well correlated enthalpy–entropy compensation was observed. The analyses showed C C C (Me) and C C C (Et) behaved similarly in terms of thermodynamics of micellization, but they behaved differently from C C C (Pr) and C C C (Bu), which could be ascribed to the hydrophobicity and the location of the headgroup alkyl chains in the aggregates. These initial results indicate the headgroup alkyl chain plays an important role in influencing the thermodynamic properties of gemini surfactants.
    Keywords: Gemini Surfactants ; Headgroup ; Micellization ; Thermodynamic Properties ; Enthalpy–Entropy Compensation ; Engineering ; Chemistry
    ISSN: 0021-9797
    E-ISSN: 1095-7103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Nurse Education Today, July 2012, Vol.32(5), pp.570-575
    Description: To equip undergraduate nursing students with basic knowledge and skills and foster positive attitudes toward evidence-based practice (EBP), a pilot learning program during their clinical practicum was developed in a teaching hospital in China. This article describes the specific learning process through which self-directed learning and workshop strategies were used, and a pre- and post-intervention survey were conducted to evaluate the effectiveness of the learning strategies. The findings show a significant improvement in their perceptions of EBP knowledge, attitudes and beliefs, and behavior levels. Beginning competencies in EBP were achieved. Participants reported great satisfaction and have found this program helpful in promoting their analytical and problem-solving abilities, independent learning ability, and cooperative and communication abilities as well. ► Self-directed learning combined with workshop strategy is first used in EBP learning. ► Beginning competencies in EBP and positive attitudes were achieved in the process. ► A set of SDL plan with resources and objectives for EBP learning was developed. ► Workshop strategy was proved to be beneficial for learning research evaluation skills. ► Independent learning, cooperative and communication skills were improved as well.
    Keywords: Evidence-Based Practice ; Self-Directed Learning ; Workshop ; Nursing Students ; Medicine ; Nursing
    ISSN: 0260-6917
    E-ISSN: 1532-2793
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: FEBS Letters, 21 September 2012, Vol.586(19), pp.3391-3397
    Description: ► CypM can methylate both α-N-terminal amino groups and lysine ε-amino groups. ► CypM methylates a variety of cyclic peptides such as nisin and haloduracin. ► α- -methyltransferases did not evolve as a specific clade. The posttranslational methylation of N-terminal α-amino groups (α-N-methylation) is a ubiquitous reaction found in all domains of life. Although this modification usually occurs on protein substrates, recent studies have shown that it also takes place on ribosomally synthesized natural products. Here we report an investigation of the bacterial α- -methyltransferase CypM involved in the biosynthesis of the peptide antibiotic cypemycin. We demonstrate that CypM has low substrate selectivity and methylates a variety of oligopeptides, cyclic peptides such as nisin and haloduracin, and the ε-amino group of lysine. Hence it may have potential for enzyme engineering and combinatorial biosynthesis. Bayesian phylogenetic inference of bacterial α- -methyltransferases suggests that they have not evolved as a specific group based on the chemical transformations they catalyze, but that they have been acquired from various other methyltransferase classes during evolution.
    Keywords: Α-N-Methyltransferase ; Peptide Antibiotic ; Lantibiotic ; Catalytic Promiscuity ; Evolution ; Biology ; Chemistry ; Anatomy & Physiology
    ISSN: 0014-5793
    E-ISSN: 1873-3468
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Social Behavior and Personality: an international journal, August, 2010, Vol.38(7), p.929(11)
    Description: We empirically investigated the antecedents and effects of local political trust. The survey data (N = 424) were collected during postearthquake rehabilitation and reconstruction in China's Sichuan province in 2008. Findings indicate that local political trust is shaped not only by policy appraisal, but also by perceptions of informational and emotional support from the local government. The attitudinal and behavioral consequences of trust suggest that the more that people trust, the more positive will be their evaluation of the local government, and the more resources they will be willing to allocate to communal facilities. Finally, the theoretical and applied implications of this study are discussed. Keywords: local political trust, policy appraisal, perceived support, postearthquake.
    Keywords: Trust (Psychology) -- Research ; Social Support -- Research
    ISSN: 0301-2212
    E-ISSN: 11796391
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages