Raman Spectroscopy of Insulin under Ambient and Extreme Conditions

Raman spectroscopy has been used to investigate different conformational states of bovine pancreatic insulin: the native form and several structurally modified states with different extent of denaturation induced by thermo-chemical treatment and by applying very high pressure (up to 8 GPa) using a diamond anvil cell. High-pressure results confirm the peculiar strength-tovolume compression of insulin and largely extend the pressure range of its structural stability (0–4.2 GPa). Above 4.2 GPa, insulin undergoes an irreversible structural transition that, once pressure is released, leaves the sample in a new conformational state. The protein secondary structure after the pressure treatment results to be somehow intermediate between the native and the thermo-chemical fibrillar samples. The analysis of the pressure dependence of the Raman spectrum and of several specific spectroscopic markers allows us to follow the path from the native to new pressure-denatured protein conformation. Morover a refolding studies has been conducted on fibrillar samples of insulin and lysozyme by means of ammonium based ionic liquids

Interaction of a Long Alkyl Chain Protic Ionic Liquid and Water

A combined experimental/theoretical approach has been used to investigate the role of water in modifying the microscopic interactions characterizing the optical response of butyl-ammonium nitrate (BAN) water solutions. Raman spectra, dominated by the signal from the protic ionic liquid, were collected as a function of the water content, and the corresponding spatial organization of the ionic couples, as well as their local arrangement with water molecules, was studied exploiting classical molecular dynamics calculations. High quality spectroscopic data, combined with a careful analysis, revealed that water affects the vibrational spectrum BAN in solution: as the water concentration is increased, peaks assigned to stretching modes show a frequency hardening together with a shape narrowing, whereas the opposite behavior is observed for peaks assigned to bending modes. Calculation results clearly show a nanometric spatial organization of the ionic couples that is not destroyed on increasing the water content at least within an intermediate range. Our combined results show indeed that small water concentrations even increase the local order. Water molecules are located among ionic couples and are closer to the anion than the cation, as confirmed by the computation of the number of H-bonds which is greater for water-anion than for water-cation. The whole results set thus clarifies the microscopic scenario of the BAN-water interaction and underlines the main role of the extended hydrogen bond network among water molecules and nitrate anions.Comment: 27 pages, 10 figure

Role of ionic liquids in protein refolding: native/fibrillar versus treated lysozyme

Several ionic liquids (ILs) are known to revert aggregation processes and improve the in vitro refolding of denatured proteins. In this paper the capacity of a particular class of ammonium based ILs to act as refolding enhancers was tested using lysozyme as a model protein. Raman spectra of ILs treated fibrillar lysozyme as well as lysozyme in its native and fibrillar conformations were collected and carefully analyzed to characterize the refolding extent under the effect of the IL interaction. Results obtained confirm and largely extend the earlier knowledge on this class of protic ILs and indicate Ethyl Ammonium Nitrate (EAN) as the most promising additive for protein refolding. The experiment provides also the demonstration of the high potentiality of Raman spectroscopy as a comprehensive diagnostic tool in this field.Comment: 11 pages, 6 figures, 3 table

industrializzazione di un nuovo processo produttivo: il progetto kodak, philip morris manufacturing & technology

Considerando il mercato odierno, a causa della globalizzazione, le aziende sono costrette a produrre prodotti a basso costo senza rinunciare alla qualità, solo così riescono a restare competitive sul mercato. Di conseguenza, è necessario migliorare continuamente i processi di produzione (Kaizen). Uno degli elementi chiavi per raggiungere questo obiettivo è la manutenzione perché permette di migliorare il livello di utilizzabilità e disponibilità degli impianti, aumentando l’efficienza globale della linea. Un altro aspetto portato dalla globalizzazione è lo sviluppo di prodotti che siano in grado di assicurare un vantaggio competitivo all'azienda. L'azienda Philip Morris International ha dunque sviluppato un prodotto innovativo in grado di posizionarla sul mercato con una posizione di first mover. Nel caso di studio per assicurare bassi costi produttivi, alta qualità ed efficienza, è stata svolta una fase di industrializzazione del prodotto, precedente alla fase di produzione. L'obiettivo di questa fase era garantire che il processo produttivo del nuovo prodotto, rispettasse fin dall'inizio gli standard della Lean Manufacturing applicati in azienda. Per monitorare ed efficientare il processo è stato utilizzato l'indice l’Overall Equipment Effectiveness (OEE) che permette di misurare l’efficacia delle operazioni di produzione di tutto il sistema studiato

A new CLT system for masonry construction refurbishment

In Italy about 50% of the building heritage has a masonry structure. The refurbishment of these buildings is a delicate issue. The complexity of the problem lies in the presence of a widespread panorama behind the category masonry construction because their characteristics depend on different techniques related to local traditions. The current conditions are often the result of a large number of subsequent interventions and of their natural decay. The complex scenery requires a diversified range of solutions in order to find an ‘ad hoc’ answer for each case. Nowadays energy efficiency requirements need a multidisciplinary approach, as structure safety oriented strategies are no longer sufficient. An environmental performance upgrade is needed. In this panorama there are some buildings with a so advanced decay that trying to preserve the whole building envelope could lead to lose it. The façadism allows the construction of a new building within the historic façades. This paper proposes a method for the refurbishment of these buildings based on the use of Cross Laminated Timber technology. The research focuses on the study of a standard process that ensures the highest building quality

Heterogeneity of propyl-ammonium nitrate solid phases obtained under high pressure

A recent work reported on different solid phases obtained on the protic ionic liquid propyl-ammonium nitrate (PAN) under a pressure up to 2 GPa. However, the experimental parameters and measurement protocols driving the solidification process were not clarified. Here, we report on and discuss three different Raman measurements on PAN carried out over different pressure ranges (up to 4 GPa). Exploiting different pressure increasing rates for each measurement we obtained a variety of solid phases. The differences between these phases are highlighted by visual inspection, by different solidification pressure values and by the Raman spectroscopic features relative to the anion stretching mode and to the cation alkyl chain vibration. Our results indicate different local structures surrounding the ionic couple in the solid phase and the capability of pressure to lock the cation alkyl chain in conformations different from those of the liquid state. These evidences also suggest the use of systematic and careful measurement protocols in order to reproduce a particular solid phase of PAN under pressure. (C) 2014 Elsevier Ltd. All rights reserved

Raman analysis of insulin denaturation induced by high-pressure and thermal treatments

Raman spectroscopy has been used to investigate different conformational states of bovine pancreatic insulin: the native form and several structurally modified states with different extent of denaturation induced by thermo-chemical treatment and by applying very high pressure (up to 8GPa) using a diamond anvil cell. High-pressure results confirm the peculiar strength to volume compression of insulin and largely extend the pressure range of its structural stability (0-4.2GPa). Above 4.2GPa, insulin undergoes an irreversible structural transition that, once pressure is released, leaves the sample in a new conformational state. The protein secondary structure after the pressure treatment results in a structure that is somewhat intermediate between that of the native and the thermo-chemical fibrillar samples. The analysis of the pressure dependence of the Raman spectrum and of several specific spectroscopic markers allows us to follow the path from the native to new pressure-denatured protein conformation. Copyright © 2011 John Wiley & Sons, Ltd