Top-down analysis of immunoglobulin G isotypes 1 and 2 with electron transfer dissociation on a high-field Orbitrap mass spectrometer

The increasing importance of immunoglobulins G (IgGs) as biotherapeutics calls for improved structural characterization methods designed for these large (~ 150 kDa) macromolecules. Analysis workflows have to be rapid, robust, and require minimal sample preparation. In a previous work we showed the potential of Orbitrap Fourier transform mass spectrometry (FTMS) combined with electron transfer dissociation (ETD) for the top-down investigation of an intact IgG1, resulting in ~ 30% sequence coverage. Here, we describe a top-down analysis of two IgGs1 (adalimumab and trastuzumab) and one IgG2 (panitumumab) performed with ETD on a mass spectrometer equipped with a high-field Orbitrap mass analyzer. For the IgGs1, sequence coverage comparable to the previous results was achieved in a two-fold reduced number of summed transients, which corresponds, taken together with the significantly increased spectra acquisition rate, to ~ six-fold improvement in analysis time. Furthermore, we studied the influence of ion-ion interaction times on ETD product ions for IgGs1, and the differences in fragmentation behavior between IgGs1 and IgG2, which present structural differences. Overall, these results reinforce the hypothesis that gas phase dissociation using both energy threshold-based and radical-driven ion activations is directed to specific regions of the polypeptide chains mostly by the location of disulfide bonds

Датчик угла шарового гироскопа

При работе с гироскопическим прибором, важнейшим информационным параметром является угловое положение оси вращения ротора, относительно корпуса прибора. Существует много различных способов съема угловой информации, подходящих под ту или иную задачу. В первую очередь, для выбора принципа работы датчика, требуется изучить конструкцию прибора, на котором будет установлен датчик угла (ДУ), и установить требования, согласно которым будет разрабатываться датчик угла. В данной работе требуется рассмотреть всевозможные типа оптических датчиков, подобрать наиболее подходящий тип, и провести исследование по возможному использованию данного датчика на имеющейся конструкции гироскопического прибора с газодинамической подвесом шарового ротора.When working with a gyro instrument, the most important information parameter is the angular position of the axis of rotation of the rotor, relative to the body of the device. There are many different ways to remove the angular information, suitable for a particular task. First of all, to select the principle of the sensor, it is required to study the design of the device on which the angle sensor will be installed and establish the requirements according to which the angle sensor will be developed. In this paper, it is required to consider all possible types of optical sensors, to select the most suitable type, and to conduct a study on the possible use of this sensor on the existing design of a gyroscopic device with a gas-dynamic suspension of a spherical rotor

Relative acidic compartment volume as a lysosomal storage disorder–associated biomarker

Lysosomal storage disorders (LSDs) occur at a frequency of 1 in every 5,000 live births and are a common cause of pediatric neurodegenerative disease. The relatively small number of patients with LSDs and lack of validated biomarkers are substantial challenges for clinical trial design. Here, we evaluated the use of a commercially available fluorescent probe, Lysotracker, that can be used to measure the relative acidic compartment volume of circulating B cells as a potentially universal biomarker for LSDs. We validated this metric in a mouse model of the LSD Niemann-Pick type C1 disease (NPC1) and in a prospective 5-year international study of NPC patients. Pediatric NPC subjects had elevated acidic compartment volume that correlated with age-adjusted clinical severity and was reduced in response to therapy with miglustat, a European Medicines Agency–approved drug that has been shown to reduce NPC1-associated neuropathology. Measurement of relative acidic compartment volume was also useful for monitoring therapeutic responses of an NPC2 patient after bone marrow transplantation. Furthermore, this metric identified a potential adverse event in NPC1 patients receiving i.v. cyclodextrin therapy. Our data indicate that relative acidic compartment volume may be a useful biomarker to aid diagnosis, clinical monitoring, and evaluation of therapeutic responses in patients with lysosomal disorders

Abstracts from the 8th International Conference on cGMP Generators, Effectors and Therapeutic Implications

This work was supported by a restricted research grant of Bayer AG

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

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