93 research outputs found

    Enhanced Stability Differentiation of Therapeutic Polyclonal Antibodies with All Ion Unfolding-Ion Mobility-Mass Spectrometry

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    Compared with monoclonal antibodies, polyclonal antibodies (pAbs) have rather significant characteristics, including lower cost, shorter production cycle, and higher affinity. Therefore, to facilitate their applications in clinic, it is equally critical to comprehensively characterize the conformational stabilities of pAb at the molecular weight-resolved scale, which is technically challenging due to the lack of an effective analytical tool capable of simultaneously providing both stability and molecular weight information within an acceptable error range. Ion mobility-mass spectrometry (IM-MS) has grown as an alternative to rapidly assess protein conformational stability with accurate molecular weight information maintained, especially when equipped with a collision-induced unfolding (CIU) regime. Dynamic and transient conformational intermediates can be captured with the CIU-IM-MS technique, adding to traditional static structural measurements with collisional cross section. Most CIU-IM-MS-centered protocols are focusing on the application to isolated, targeted protein ions, namely, analyzing one single charge state at one time, limiting its analytical throughput and speed. In this study, we employed an enhanced unfolding regime, all ion unfolding (AIU), capable of the simultaneous operation of numerous ions at a time during stepped unfolding processes to analyze pAb. Results show that AIU can quantitatively characterize the subtle differences in conformational stability among four structurally similar pAbs with improved resolving capability by around a 2–4-fold increment in both stability and structure differentiating parameters. Besides, AIU also benefits from considerably saved time cost and improved spectrum quality with an elevated signal-to-noise ratio

    Funnel plot for the random-effects between-group meta-analysis on blood glutamate levels in persons with ASD and controls.

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    <p>Funnel plot for the random-effects between-group meta-analysis on blood glutamate levels in persons with ASD and controls.</p

    Forest plot for the random-effects between-group meta-analysis of blood glutamate levels in persons with ASD and controls.

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    <p>Forest plot for the random-effects between-group meta-analysis of blood glutamate levels in persons with ASD and controls.</p

    Meta-regression of blood glutamate levels in persons with ASD and controls.

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    <p>Meta-regression of blood glutamate levels in persons with ASD and controls.</p

    Characteristics of the twelve studies included in the meta-analysis.

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    <p>Characteristics of the twelve studies included in the meta-analysis.</p

    Plasma-Droplet Fusion-Mass Spectrometry Reveals Sub-Millisecond Protein Unfolding Dynamics Induced by Reactive Oxygen Species

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    Investigating the connection between reactive oxygen species (ROS) and oxidative protein unfolding is critical to reveal the mechanisms underlying disease involving elevated ROS and protein misfolding. This could inform the development of therapeutics targeting cells based on their redox status. In this study, we developed a plasma-droplet fusion-mass spectrometry platform to rapidly assess protein resilience to ROS. This home-built system fuses ROS generated from the microplasma source with protein microdroplets from a tunable nanospray source. At the droplet-plasma intersection, ROS interact with proteins before entering the mass spectrometer for mass identification and structural characterization. Benefiting from the small-sized microdroplet with adjustable traveling velocity, the platform enables the first sub-millisecond kinetic study of ROS-induced protein unfolding, with a rate constant of approximately 1.81 ms–1. Capturing ROS-induced protein unfolding intermediates and the resultant ligand release dynamics can be extended to many more protein systems. We foresee broad applications for establishing previously undetected protein unfolding events when biologically impactful ROS are enriched in time and space with functional proteins and complexes

    Summary of the results of blood glutamate levels in persons with ASD and controls.

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    <p>Summary of the results of blood glutamate levels in persons with ASD and controls.</p

    Flow chart of the study selection process for eligible studies in the systematic review.

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    <p><i>From</i>: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). <i>Preferred Reporting I</i>tems for <i>S</i>ystematic Reviews and <i>M</i>eta-<i>A</i>nalyses: The PRISMA Statement. PLoS Med 6(6): e1000097. doi: <a href="10.1371/journal.pmedl000097" target="_blank">10.1371/journal.pmedl000097</a> For more information, visit <a href="http://www.prisma-statement.org" target="_blank">www.prisma-statement.org</a>.</p
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