38 research outputs found

    Online Data Condensation for Digitalised Biopharmaceutical Processes

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    Efficient control of a bioprocess relies on the ability to systematically capture and represent the process dynamics of critical process parameters. Multivariate monitoring techniques in biopharmaceuticals has resulted in the generation of large amounts of data comprising real-time measurements of critical quality and performance attributes. If exploited efficiently, these can provide an opportunity for developing better control action. For this, it is important to have a comprehensive view of the critical process parameter landscape, which can only be achieved by integrating both online and offline data into a single data matrix that can then be subjected to standard data analysis protocols. However, owing to the difference in the number of readings available for variables recorded online and offline, there is a need for new methods to achieve condensation capability. This paper introduces a novel methodology for condensing online data into an offline data matrix, which performed better when compared to traditionally employed averaging and helped increase the number of variables available for representing the design space of the process. The method was also used to understand how error propagates through online data, so as to identify an interval of tolerance in online monitoring of bioprocesses

    Preferential adsorption to air-water interfaces: a novel cryoprotective mechanism for LEA proteins

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    Late embryogenesis abundant (LEA) proteins comprise a diverse family whose members play a key role in abiotic stress tolerance. As intrinsically disordered proteins, LEA proteins are highly hydrophilic and inherently stress tolerant. They have been shown to stabilize multiple client proteins under a variety of stresses, but current hypotheses do not fully explain how such broad range stabilization is achieved. Here, using neutron reflection and surface tension experiments, we examine in detail the mechanism by which model LEA proteins, AavLEA1 and ERD10, protect the enzyme citrate synthase from aggregation during freeze-thaw. We find that a major contributing factor to citrate synthase aggregation is the formation of air bubbles during the freeze-thaw process. This greatly increases the air-water interfacial area, which is known to be detrimental to folded protein stability. Both model LEA proteins preferentially adsorb to this interface and compete with citrate synthase, thereby reducing surface induced aggregation. This novel surface activity provides a general mechanism by which diverse members of the LEA protein family might function to provide aggregation protection that is not specific to the client protein.Canadian Research Council for PhD studentship + ERC gran

    Conformational change of the AcrR regulator reveals a possible mechanism of induction

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    The Escherichia coli AcrR multidrug-binding protein represses transcription of acrAB and is induced by many structurally unrelated cytotoxic compounds. The crystal structure of AcrR in space group P2221 has been reported previously. This P2221 structure has provided direct information about the multidrug-binding site and important residues for drug recognition. Here, a crystal structure of this regulator in space group P31 is presented. Comparison of the two AcrR structures reveals possible mechanisms of ligand binding and AcrR regulation

    Myelinosome formation represents an early stage of oligodendrocyte damage in multiple sclerosis and its animal model

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    Oligodendrocyte damage is a central event in the pathogenesis of the common neuro-inflammatory condition, multiple sclerosis (MS). Where and how oligodendrocyte damage is initiated in MS is not completely understood. Here, we use a combination of light and electron microscopy techniques to provide a dynamic and highly resolved view of oligodendrocyte damage in neuroinflammatory lesions. We show that both in MS and in its animal model structural damage is initiated at the myelin sheaths and only later spreads to the oligodendrocyte cell body. Early myelin damage itself is characterized by the formation of local myelin out-foldings-'myelinosomes'-, which are surrounded by phagocyte processes and promoted in their formation by anti-myelin antibodies and complement. The presence of myelinosomes in actively demyelinating MS lesions suggests that oligodendrocyte damage follows a similar pattern in the human disease, where targeting demyelination by therapeutic interventions remains a major open challenge

    Conformational change of the AcrR regulator reveals a possible mechanism of induction

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    The Escherichia coli AcrR multidrug-binding protein represses transcription of acrAB and is induced by many structurally unrelated cytotoxic compounds. The crystal structure of AcrR in space group P2221 has been reported previously. This P2221 structure has provided direct information about the multidrug-binding site and important residues for drug recognition. Here, a crystal structure of this regulator in space group P31 is presented. Comparison of the two AcrR structures reveals possible mechanisms of ligand binding and AcrR regulation.This article is from Acta Crystallographica Section F 64 (2008): 584, doi:10.1107/S1744309108016035. Posted with permission.</p
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