110 research outputs found

    Evolution of the bancassurance concept: banking and insurance associations

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    This article intends to discuss the determinants of the evolution of banking-insurance relations in the global dimension.The simultaneous complementarity and substitutability of the offer of banking and insurance services in businesspractice led to a tendency to integrate the activities of banks and insurance companies in search of new distributionchannels, such as bancassurance. Hence, the aim of the article is an attempt to present the genesis, historical adaptation,definition, and the essence of the bancassurance concept. The basic question that guides the considerations hererelates to the symmetry of development, namely: has the phenomenon of integration of financial institutions under thebancassurance concept developed at the same pace and adopted the same paradigm in each country? To achieve thisgoal, the literature on the subject and intranet resources from the canon of the financial market were used. The backgroundof the analysis is the experience of countries around the world where the idea of banking and insurance interactionswas found.Moreover, the article discusses the determinants, models, and forms of bancassurance, as well as indicates the epicenterof its practices and presents the phases (periods) of its development. Moreover, the problem of the lack of uniformand commonly used in the literature on the subject as well as in the economic practice of defining the concepts of bankingand insurance connections was analyzed

    Use of a charge reducing agent to enable intact mass analysis of cysteine-linked antibody-drug-conjugates by native mass spectrometry

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    AbstractAntibody-drug-conjugates (ADC) are a growing class of anticancer biopharmaceuticals. Conjugation of cysteine linked ADCs, requires initial reduction of mAb inter-chain disulfide bonds, as the drugs are attached via thiol chemistry. This results in the active mAb moiety being transformed from a covalently linked tetramer to non-covalently linked complexes, which hinders precise determination of drug load with LC–MS. Here, we show how the addition of the charge reducing agent triethylammonium acetate (TEAA) preserves the intact mAb structure, is well suited to the study of cysteine linked conjugates and facilitates easy drug load determination by direct infusion native MS

    Investigation of large protein and multimeric protein complex structures with mass spectrometry techniques

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    The biophysical properties, biological activity and function of macromolecular systems are highly dependent on their structure. Structure-activity relationships of proteins and their binding partners are critical for drug discovery, biochemical and medical research. While the gas-phase environment might present as an unusual venue from which to explore protein structure, for over the past two decades, nano-electrospray ionization (nESI) coupled to mass spectrometry (MS) has been recognized as having great potential for analysis of protein structure and protein non-covalent complexes. In conjunction with related technique of ion mobility (IM), mass spectrometry (IM-MS) provides insights into protein native-like conformations and any structural changes in may undergo upon ligand binding or alternations induced via physical parameters such as temperature, pressure or solution conditions. As most proteins tend to exist as multiple domains; from the distribution of oligomeric states in the Protein Data Base (PDB) 86% of proteins exist as oligomers; the work presented in this thesis focuses on application of MS techniques to probe the tertiary and quaternary structure of various large and multimeric protein complexes, their dynamics and/or conformational changes. Wherever relevant, the gas-phase studies reported here are complemented by other techniques, such as hydrogen deuterium exchange MS (HDX), molecular modelling (MD) and analytical ultracentrifugation (AUC). Firstly, the dynamics of intact monoclonal antibodies (mAbs) and their fragments are explored with IM-MS. Variations observed in conformational landscapes occupied by two mAb isotypes are rationalized by differences in disulfide linkages and non-covalent interactions between the antibody peptide chains. Moreover, mAb intrinsic flexibility is compared to other multimeric protein complexes in terms of collision cross section distribution span. Secondly, variable temperature MS (VT-MS) and variable temperature IM-MS (IM-MS) are used to probe unfolding and dissociation of four standard multimeric protein complexes (TTR, avidin, conA and SAP) as a function of the of analysis environment temperature. VT-MS is found to allow for decoupling of their melting temperature (Tm) from the protein complex dissociation temperature (TGPD). Whereas, VT-IM-MS is used to investigate structural changes of these protein complexes at elevated temperatures and provide insights into the thermally induced dissociation (TID) mechanism, as well as strength of the non-covalent interactions between subunits. Thirdly, VT-(IM)-MS methodology is applied to study behaviour of three mAbs: IgG1, IgG4 and an engineered IgG4 of increased thermal stability. Such analysis shows to be promising for comparative thermal stability studies for proteins of therapeutic interest. Lastly, the structure of ATP-phosphoribosyltransferase (MtATPPRT), an enzyme catalysing the first step of the biosynthesis of L-histidine in Mycobacterium tuberculosis, is explored. Conformational changes occurring upon feedback allosteric inhibition by L-histidine are probed with MS, IM-MS, HDX-MS and AUC. Reported results serve as the basis for IM-MS/HDX-MS based screening method to be used for screening of a library of novel and promising anti-tuberculosis agents

    Student jako weryfikator jakości usługi edukacyjnej oferowanej przez polskie uczelnie wyższe. Wyniki badań wstępnych

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    Celem artykułu jest próba znalezienia odpowiedzi na pytanie: jaki jest poziom zadowolenia studentów z jakości usługi edukacyjnej w ramach kształcenia akademickiego, a także sprawdzenie, czy istnieją istotne statystycznie zależności pomiędzy obszarami determinującymi jakość tej usługi a czynnikami opisującymi cechy respondentów. Analizę i opis oparto na badaniach przeprowadzonych wśród studentów zarządzania w różnych ośrodkach akademickich na terenie Polski. W badaniu ankietowym zastosowano wskaźnik satysfakcji klienta i wykazano, że istnieje niedomiar jakości, a najważniejszymi obszarami determinującymi jakość są: szybkość i niezawodność. Kolejna część badania dotycząca analizy współzależności wykazała, że każdy z badanych i analizowanych obszarów jakości usługi został co najmniej cztery razy zróżnicowany w odniesieniu do wszystkich z badanych zmiennych

    Tandem Mass Spectrometric Analysis of Novel Peptide-Modified Gemini Surfactants Used as Gene Delivery Vectors.

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    NSERC, CIHR, CFIDiquaternary ammonium gemini surfactants have emerged as effective gene delivery vectors. A novel series of 11 peptide-modified compounds was synthesized, showing promising results in delivering genetic materials. The purpose of this work is to elucidate the tandem mass spectrometric (MS/MS) dissociation behavior of these novel molecules establishing a generalized MS/MS fingerprint. Exact mass measurements were achieved using a hybrid quadrupole orthogonal time-of-flight mass spectrometer, and a multi-stage MS/MS analysis was conducted using a triple quadrupole-linear ion trap mass spectrometer. Both instruments were operated in the positive ionization mode and are equipped with electrospray ionization. Abundant triply charged [M+H]3+ species were observed in the single-stage analysis of all the evaluated compounds with mass accuracies of less than 8 ppm in mass error. MS/MS analysis showed that the evaluated gemini surfactants exhibited peptide-related dissociation characteristics because of the presence of amino acids within the compounds' spacer region. In particular, diagnostic product ions were originated from the neutral loss of ammonia from the amino acids' side chain resulting in the formation of pipecolic acid at the N-terminus part of the gemini surfactants. In addition, a charge-directed amide bond cleavage was initiated by the amino acids' side chain producing a protonated α-amino-ε-caprolactam ion and its complimentary C-terminus ion that contains quaternary amines. MS/MS and MS3 analysis revealed common fragmentation behavior among all tested compounds, resulting in the production of a universal MS/MS fragmentation pathway

    Interfacing low-energy SAW nebulization with liquid chromatography-mass spectrometry for the analysis of biological samples

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    Soft ionization methods for the introduction of labile biomolecules into a mass spectrometer are of fundamental importance to biomolecular analysis. Previously, electrospray ionization (ESI) and matrix assisted laser desorption-ionization (MALDI) have been the main ionization methods used. Surface acoustic wave nebulization (SAWN) is a new technique that has been demonstrated to deposit less energy into ions upon ion formation and transfer for detection than other methods for sample introduction into a mass spectrometer (MS). Here we report the optimization and use of SAWN as a nebulization technique for the introduction of samples from a low flow of liquid, and the interfacing of SAWN with liquid chromatographic separation (LC) for the analysis of a protein digest. This demonstrates that SAWN can be a viable, low-energy alternative to ESI for the LC-MS analysis of proteomic samples

    Mechanisms of iron- and O2-sensing by the [4Fe-4S] cluster of the global iron regulator RirA

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    RirA is a global regulator of iron homeostasis in Rhizobium and related α-proteobacteria. In its [4Fe-4S] cluster-bound form it represses iron uptake by binding to IRO Box sequences upstream of RirA-regulated genes. Under low iron and/or aerobic conditions, [4Fe-4S] RirA undergoes cluster conversion/degradation to apo-RirA, which can no longer bind IRO Box sequences. Here, we apply time-resolved mass spectrometry and electron paramagnetic resonance spectroscopy to determine how the RirA cluster senses iron and O2. The data indicate that the key iron-sensing step is the O2-independent, reversible dissociation of Fe2+ from [4Fe-4S]2+ to form [3Fe-4S]0. The dissociation constant for this process was determined as Kd = ~3 µM, which is consistent with the sensing of ‘free’ iron in the cytoplasm. O2-sensing occurs through enhanced cluster degradation under aerobic conditions, via O2-mediated oxidation of the [3Fe-4S]0 intermediate to form [3Fe-4S]1+. This work provides a detailed mechanistic/functional view of an iron-responsive regulator
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