2,461 research outputs found

    Reductive Biotransformation of Ethyl Acetoacetate: A Comparative Studies using Free and Immobilized Whole Yeast Cells

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    Bioreduction of ethyl acetoacetate with free and immobilized yeast whole cell was achieved by using water and sucrose combination. After detachment from immobilized beads under basic condition, the corresponding ethyl(S)-(+)-3-hydroxybutanoate was isolated with 98 to 100% yield. Immobilized beads of yeast whole cell were prepared at different temperature which affects the morphology and physiology of the beads for the diffusion of the enzyme, which shown the maximum conversion of the substrate to products as compared to the free yeast whole cell

    “BE YOURSELF” (the Creation of a Music Composition)

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    An artistic workmanship is a creative work process of an artist in creating artworks. Artwork meant by the writer is "Be Yourself", which is related to the establishment of his self-characters that grown up in Sundanese culture. Life journey was a dynamic process and became the will of the Almighty. God's destiny and life journey made the writer as “urangsumando” (people related by marriage) in Minangkabau. Cross-cultural was a life journey to be (yourself) and the destiny he should do – being in two different culture positions. Such differences did not automatically make the writer soluble in integration – he existed in two conceptions. In the realization, how the concepts are able to deliver other offers which have contribution to the development of artistic creation. The discussion in this article is the artistic forms as the exploration, working material, and forms of performance

    Free Energy Self-Averaging in Protein-Sized Random Heteropolymers

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    Current theories of heteropolymers are inherently macrpscopic, but are applied to folding proteins which are only mesoscopic. In these theories, one computes the averaged free energy over sequences, always assuming that it is self-averaging -- a property well-established only if a system with quenched disorder is macroscopic. By enumerating the states and energies of compact 18, 27, and 36mers on a simplified lattice model with an ensemble of random sequences, we test the validity of the self-averaging approximation. We find that fluctuations in the free energy between sequences are weak, and that self-averaging is a valid approximation at the length scale of real proteins. These results validate certain sequence design methods which can exponentially speed up computational design and greatly simplify experimental realizations.Comment: 4 pages, 3 figure

    Flyash lime gypsum bricks - A boon for Vidarbha region

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    Flyash line gypsum bricks are much superior to conventional clay bricks available in the Vidarbha region. This fact has been established by the authors through extensive research work. Need of the hour is to give proper technical support to the manufacturers of the fly ash bricks and to provide proper facilities to monitor the quality of these bricks so as to make them popular and acceptable to the consumers

    The Roles of Entropy and Kinetics in Structure Prediction

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    Background: Here we continue our efforts to use methods developed in the folding mechanism community to both better understand and improve structure prediction. Our previous work demonstrated that Rosetta’s coarse-grained potentials may actually impede accurate structure prediction at full-atom resolution. Based on this work we postulated that it may be time to work completely at full-atom resolution but that doing so may require more careful attention to the kinetics of convergence. Methodology/Principal Findings: To explore the possibility of working entirely at full-atom resolution, we apply enhanced sampling algorithms and the free energy theory developed in the folding mechanism community to full-atom protein structure prediction with the prominent Rosetta package. We find that Rosetta’s full-atom scoring function is indeed able to recognize diverse protein native states and that there is a strong correlation between score and Ca RMSD to the native state. However, we also show that there is a huge entropic barrier to folding under this potential and the kinetics of folding are extremely slow. We then exploit this new understanding to suggest ways to improve structure prediction. Conclusions/Significance: Based on this work we hypothesize that structure prediction may be improved by taking a more physical approach, i.e. considering the nature of the model thermodynamics and kinetics which result from structur

    Random walks in the space of conformations of toy proteins

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    Monte Carlo dynamics of the lattice 48 monomers toy protein is interpreted as a random walk in an abstract (discrete) space of conformations. To test the geometry of this space, we examine the return probability P(T)P(T), which is the probability to find the polymer in the native state after TT Monte Carlo steps, provided that it starts from the native state at the initial moment. Comparing computational data with the theoretical expressions for P(T)P(T) for random walks in a variety of different spaces, we show that conformational spaces of polymer loops may have non-trivial dimensions and exhibit negative curvature characteristic of Lobachevskii (hyperbolic) geometry.Comment: 4 pages, 3 figure

    Two State Behavior in a Solvable Model of β\beta-hairpin folding

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    Understanding the mechanism of protein secondary structure formation is an essential part of protein-folding puzzle. Here we describe a simple model for the formation of the β\beta-hairpin, motivated by the fact that folding of a β\beta-hairpin captures much of the basic physics of protein folding. We argue that the coupling of ``primary'' backbone stiffness and ``secondary'' contact formation (similar to the coupling between the ``secondary'' and ``tertiary'' structure in globular proteins), caused for example by side-chain packing regularities, is responsible for producing an all-or-none 2-state β\beta-hairpin formation. We also develop a recursive relation to compute the phase diagram and single exponential folding/unfolding rate arising via a dominant transition state.Comment: Revised versio
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