254 research outputs found
Liquid phase separation techniques for the characterization of monoclonal antibodies and bioconjugates
Get PDFThe characterization of biopharmaceuticals is a challenging task due to the structural complexity of such products. During both manufacturing and storage, biopharmaceuticals are exposed to a high risk of undergoing several desired and undesired chemical and enzymatic modifications. Final products are therefore heterogeneous mixtures of quite diverse chemical entities, rather than titrated blends of molecules. For this reason, the development of advanced separation techniques is paramount to allow the characterization of the different constituents of biopharmaceuticals. Several separation methods have been reported so far, each one based on specific physicochemical mechanism and uniquely suited for the characterization of distinctive product features, called Critical Quality Attributes (CQAs). If such diversity offers on one hand a wide array of possibilities, on the other hand it raises some issues concerning regulation, validation and harmonization of the results obtained in different laboratories or by different methods. Moreover, a comprehensive characterization of biopharmaceuticals can nowadays be achieved only by multiple analyzes with orthogonal methods or by the combination of orthogonal techniques in one method. Herein, we reviewed the main variants of Liquid Chromatography (LC), Capillary Electrophoresis (CE), and other less popular liquid phase separation techniques that are used for the characterization of monoclonal Antibodies (mAbs) and Antibody Drug Conjugates (ADCs)
Benzothiadiazole derivatives endowed with STAT3 inhibition
No full textBENZOTHIADIAZOLE DERIVATIVES ENDOWED WITH STAT3
INHIBITION
Arianna Gelain (1), Matteo Mori (1), Ettore Gilardoni (1), Luca Regazzoni (1), Alessandro Pedretti (1),
Diego Colombo (2), Gary Parkinson (3), Akira Asai (4), Fiorella Meneghetti (1), Stefania Villa (1)
1) Department of Pharmaceutical Sciences, University of Milan, via L. Mangiagalli 25, 20133 Milan, Italy
2) Department of Medical Biotechnology and Translational Medicine, University of Milan, via C. Saldini 50, 20133 Milan,
Italy
3) Department of Pharmaceutical and Biological Chemistry – UCL School of Pharmacy, University College London, 29/39
Brunswick Square, WC1N 1AX London, United Kingdom
4) Center for Drug Discovery – Graduate School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku,
422-8526 Shizuoka, Japan
Signal Transducer and Activator of Transcription 3 (STAT3) is a latent cytoplasmic protein over-expressed in
various cancer cell lines1,2. As a part of our ongoing research focused on compounds showing STAT3 SH2
domain inhibiting activity3,4, by a virtual screening approach, we identified 5,6-dimethyl-1H,3H
-2,1,3-benzothiadiazole-2,2-dioxide (1) as potential inhibitor. Several derivatives were synthesized (Figure 1)
and tested. Since compound 1 exhibited the most interesting activity (IC50 = 15.8 ± 0.6 μM by
AlphaScreen-based assay), we decided to investigate the mechanism of its activity by liquid chromatography,
MS and UV studies, discovering compound 1 unexpected interaction also with cysteine residues5.
Figure 1 . Benzothiadiazole-2,2-dioxide derivatives set
References
1) Darnell, J. Jr Science, 1997, 277, 1630-1635
2) Turkson, J. and Jove R. Oncogene, 2000, 19, 6613-6626
3) Meneghetti, F.; Villa, S.; Masciocchi, D.; Barlocco, D.; Toma, L.; Han, D.C.; Kwon, B.M.; Ogo, N.; Asai, A.; Legnani, L.;
Gelain, A. European J. Org. Chem. 2015, 2015, 4907–4912
4) Porta, F.; Facchetti, G.; Ferri, N.; Gelain, A.; Meneghetti, F.; Villa, S.; Barlocco, D.; Masciocchi, D.; Asai, A.; Miyoshi,
N.; Marchianò, S.; Kwon, B.M.; Jin, Y.; Gandin, V.; Marzano, C.; Rimoldi, Eur. J. Med. Chem. 2017, 131, 196–206
5) Mori, M.; Gilardoni, E.; Regazzoni, L.; Pedretti, A.; Colombo, D.; Parkinson, G.; Asai, A,; Meneghetti, F.; Villa, S.;
Gelain, A., Molecules 2020, 25(15), 3509
Cyclo(His-Pro) Exerts Protective Carbonyl Quenching Effects through Its Open Histidine Containing Dipeptides
Get PDFCyclo(His-Pro) (CHP) is a cyclic dipeptide which is endowed with favorable pharmacokinetic properties combined with a variety of biological activities. CHP is found in a number of protein-rich foods and dietary supplements. While being stable at physiological pH, CHP can open yielding two symmetric dipeptides (His-Pro, Pro-His), the formation of which might be particularly relevant from dietary CHP due to the gastric acidic environment. The antioxidant and protective CHP properties were repeatedly reported although the non-enzymatic mechanisms were scantly investigated. The CHP detoxifying activity towards α,β unsaturated carbonyls was never investigated in detail, although its open dipeptides might be effective as already observed for histidine containing dipeptides. Hence, this study investigated the scavenging properties of TRH, CHP and its open derivatives towards 4-hydroxy-2-nonenal. The obtained results revealed that Pro-His possesses a marked activity and is more reactive than l-carnosine. As investigated by DFT calculations, the enhanced reactivity can be ascribed to the greater electrophilicity of the involved iminium intermediate. These findings emphasize that the primary amine (as seen in l-carnosine) can be replaced by secondary amines with beneficial effects on the quenching mechanisms. Serum stability of the tested peptides was also evaluated, showing that Pro-His is characterized by a greater stability than l-carnosine. Docking simulations suggested that its hydrolysis can be catalyzed by serum carnosinase. Altogether, the reported results evidence that the antioxidant CHP properties can be also due to the detoxifying activity of its open dipeptides, which might be thus responsible for the beneficial effects induced by CHP containing food
Unraveling the interaction mechanism of a benzothiadiazole-2.2-dioxide derivative with STAT3 : towards novel direct inhibitors
No full textUnraveling the interaction mechanism of a benzothiadiazole-2,2-
dioxide derivative with STAT3: towards novel direct inhibitors
Matteo Mori 1, Ettore Gilardoni 1, Luca Regazzoni 1, Alessandro Pedretti 1, Diego Colombo 2,
Gary Parkinson 3, Akira Asai 4, Giulia Cazzaniga 1, Fiorella Meneghetti 1, Stefania Villa 1 and
Arianna Gelain 1
1 Department of Pharmaceutical Sciences, University of Milan, via L. Mangiagalli 25, 20133 Milan, Italy
2 Department of Medical Biotechnology and Translational Medicine, University of Milan, via C. Saldini 50,
20133 Milan, Italy
3 Department of Pharmaceutical and Biological Chemistry – UCL School of Pharmacy, University College
London, 29/39 Brunswick Square, WC1N 1AX London, United Kingdom
4 Center for Drug Discovery – Graduate School of Pharmaceutical Sciences, University of Shizuoka, 52-1
Yada, Suruga-ku, 422-8526 Shizuoka, Japan
Signal Transducer and Activator of Transcription 3 (STAT3) participates in oncogenesis by
stimulating cell proliferation and preventing apoptosis; this protein has been validated as a suitable
and selective target for anticancer therapy [1,2]. Starting from a virtual screening approach on
STAT3-SH2 domain, we identified 5,6-dimethyl-1H,3H-2,1,3-benzothiadiazole-2,2-dioxide (I) as
a potential inhibitor. Therefore, we synthesized and tested a series of derivatives (Figure 1), among
which benzosulfamide I showed a significant activity (IC50 = 15.8 ± 0.6 μM by AlphaScreen-based
assay) as a direct STAT3 inhibitor. Hence, an in-depth investigation through mass spectrometry,
liquid chromatography and UV spectroscopy studies was carried out, shedding light on its intriguing
mechanism of interaction, also involving cysteine residues located around the SH2 domain [3].
Figure 1. Benzothiadiazole derivatives of compound I.
[1] T. Bowman,. M. A. Broome, D. Sinibaldi, W. Wharton, W. J. Pledger, J. M. Sedivy, R. Irby,
T. Yeatman, S. A. Courtneidge, R. Jove, Proc. Natl. Acad. Sci. 2001, 98, 7319.
[2] J. Turkson, D. Ryan, J. S Kim, Y. Zhang, Z. Chen, E. Haura, A. Laudano, S. Sebti, A. D.
Hamilton, R. Jove, J. Biol. Chem. 2001, 276, 45443.
[3] M. Mori, E. Gilardoni, L. Regazzoni, A. Pedretti, D. Colombo, G. Parkinson, A. Asai, F.
Meneghetti, S. Villa, A. Gelain, Molecules 2020, 25(15), 3509
Ettore Majorana: unveiled genius and endless mysteries
No full textThis biography sheds new light on the life and work of physicist Ettore Majorana (including unpublished contributions), as well as on his mysterious disappearance in March 1938. Majorana is held by many, including Nobel Laureate, Enrico Fermi, to have been a genius of the rank of Galilei and Newton. In this intriguing story, the author, himself a leading expert on the work of Majorana, supplements the existing literature with new insights, anecdotes and personal accounts of contemporaries of Majorana
Postillati epicurei di Ettore Bignone
No full textSome of the books of Ettore Bignone's library once owned by the
Italian Latinist Luigi Alfonsi eventually came into the possession of
the author of the present article. Bignone was a careful reader and
added many remarks in the margins of his books; among these, several
notes on Epicurean problems are worth studying. This because Bignone
criticises well known scholars such as Constant Martha, Alfred Ernout,
and Carlo Pascal, explains difficult passages and suggests alternative
interpretations. Some of these notes have the length of a short
article, but even his very brief comments are often of high scholarly
interest
Corporate Raiders, Performance and Governance in Europe
No full text"I analyse 136 block purchases made by corporate raiders in Europe between 1990 and 2001. Contrary to the hypothesis that these investors expropriate the target companies, there is a positive market reaction to the first public announcement of these purchases. In the long-run, raiders earn an abnormal profit when they sell their stakes. When they still held their positions at the end of the sample period, abnormal returns were insignificant. Raiders' activities do not improve operating performance. The findings are consistent with superior stock picking ability among these investors, but do not support the hypothesis that raiders are governance champions." Copyright 2007 The Author Journal compilation (c) 2007 Blackwell Publishing Ltd.
O prestuplenijach i nakazanijach Č. Bekkaria. Neizdannyj perevod M.M. Ščerbatova
No full textThis article is devoted to the first Russian translation of On Crimes and Punishments, made by Mikhail Mikhailovich Shcherbatov. Particular attention is focused on the genesis of the translation: on the basis of a detailed textual analysis the author identifies as source text the Italian edition of Beccaria’s work published by Masi in 1774, and as secondary sources Catherine’s Instruction (1767) and the Elizabethan Bible of 1751. In the second part the author emphasizes the struggle between “tradition” and “rationality”, clearly evidenced in Shcherbatov, which was to become a basic element in the social and political thought of the Russian elite
How many futures on Finsler spacetime?
No full textSome recent results by the author on the geometry and dynamics of Finsler spacetimes are reviewed. It is shown that in Finslerian generalizations of general relativity the number of predicted lightlike cones is two, one past and one future, as in general relativity. This result is non-trivial as it can fail, for instance, in spacetime dimension two. It is also shown that suitable versions of the reverse Cauchy-Schwarz and reverse triangle inequalities hold on Finsler spacetimes. Finally, a long standing problem of Finslerian gravity concerns the development of dynamical equations which imply a conservation law. We make some progress following a recent proposal by the author according to which physical Finsler spacetimes have ane sphere indicatrices of hyperbolic type
Le lettere di Francesco Paolo Como a Ettore Ferrari.
No full textIn 1923 the sculptor Francesco Paolo Como (Taranto, 1888-Rome, 1973) wins the contest for the Monumento ai caduti in Taranto. As known, the realization of this work suffers many delays because of tension between the author and the various committees. Only in 1953, the last group, the Aquilifero, can be set up. The article analyses the sequence of events related to the monument through a series of missives between Como and his mentor Ettore Ferrari (Rome, 1845-1929). Through this correspondence is possible to write a clearer history of the monument and his author, explaining the reasons of Como’s anxiety, his relationship with Ferrari and his social role into the ‘fascistissima’ Taranto
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