This report describes the scientific aims and potentials as well as the preliminary technical design of IRIDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity “particle factory”, based on a combination of a high duty cycle radio-frequency superconducting electron linac and of high energy lasers. Conceived to provide unique research possibilities for particle physics, for condensed matter physics, chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of science and technology. IRIDE will contribute to open new avenues of discoveries and to address most important riddles: What does matter consist of? What is the structure of proteins that have a fundamental role in life processes? What can we learn from protein structure to improve the treatment of diseases and to design more efficient drugs? But also how does an electronic chip behave under the effect of radiations? How can the heat flow in a large heat exchanger be optimized?
The scientific potential of IRIDE is far reaching and justifies the construction of such a large facility in Italy in synergy with the national research institutes and companies and in the framework of the European and international research. It will impact also on R&D work for ILC, FEL, and will be complementarity to other large scale accelerator projects. IRIDE is also intended to be realized in subsequent stages of development depending on the assigned priorities.
A number of integral membrane G protein-coupled receptors (GPCRs) share common structural features (including palmytoilated aminoacid residues and consensus sequences specific for interaction with cholesterol) that allow them to interact with lipid rafts, membrane cholesterol-rich microdomains able to regulate GPCR signalling and functions. Among GPCRs, type-1 and type-2 cannabinoid receptors, the molecular targets of endocannabinoids (eCBs), control many physiological and pathological processes through the activation of several signal transduction pathways. Recently, the orphan GPR55 receptor has been proved to be activated by many eCBs, thus leading to the hypothesis that it might be the "type-3" cannabinoid receptor. While the biological activity of eCBs and the influence of membrane lipids on their functions are rather well established, information regarding GPR55 is still scarce and often controversial. Based on this background, here we shall review current data about GPR55 pharmacology and signalling, highlighting its involvement in several pathophysiological conditions. We shall also outline the structural features that allow GPR55 to interact with cholesterol and to associate with lipid rafts; how the latter lipid microdomains impact the biological activity of GPR55 is also addressed, as well as their potential for the discovery of new therapeutics useful for the treatment of those human diseases that might be associated with alterations of GPR55 activity.
Polyphenol oxidase (PPO) is among the most detrimental enzymes in processed plant foods, being responsible for enzymatic browning. To propose a "mild" alternative to traditional enzymatic inactivation methods, this study investigated the effect of cold atmospheric plasma (CAP) on PPO inactivation and highlighted the role of different sugars on both inactivation and structural modification of this enzyme. Different model systems were prepared in phosphate buffer using a purified PPO either alone or added with glucose, fructose, sucrose, and trehalose at different concentrations. CAP treatments (6 KV; 23 KHz; duty cycle 10%) were applied at times ranging from 5 to 30 min. Different spectroscopic analyses were conducted before and after treatments to evaluate the PPO activity and changes in tertiary and secondary structures. CAP induced a significant reduction (p < 0.05) in PPO activity across all systems, ranging from 70% to 94% after 30 min of treatment. Among sugars, fructose enhanced (p < 0.05) the PPO inactivation (+23% on average with respect to the phosphate buffer system), possibly by promoting the loss of secondary structures containing the copper-binding site of the catalytic pocket. The effect of other sugars on PPO inactivation was strictly dependent on their type and concentration; specifically, disaccharides at the highest concentrations and treatment times showed a protective effect on the structure and functionality of the protein. Thus, the results of this study highlight that sugars can modulate the effectiveness of CAP, offering promising perspectives for optimizing this food processing technology. PRACTICAL APPLICATION: Cold atmospheric plasma (CAP) is a promising nonthermal technology for food preservation. In particular, surface dielectric barrier discharge (SDBD) CAP could be applied as an alternative to chemical and thermal treatments to inactivate polyphenol oxidase (PPO), an enzyme responsible for browning reactions and quality loss in most processed fruit and vegetable products. However, as shown by this study, PPO inactivation induced by CAP is affected by sugars. Specifically, fructose can positively influence the inactivation of this enzyme. Therefore, CAP potentially could find main applications for the PPO stabilization of high fructose-content plants (e.g., pears, apples, bananas, grapes, peppers, and squashes).
Calpains are intracellular cysteine endopeptidases that combine protease activity with a dependence on Ca 2+ binding. Here we describe the conformational changes leading to the calpain activation, occurring in the enzyme purified from human erythrocytes, studied in solution using small angle X‐ray scattering (SAXS). Addition of Ca 2+ determines the formation of large soluble aggregates that can be dissociated either chelating these ions or adding cahotropic salts in solution. On the other side, our SAXS studies revealed that the addition of Ca 2+ in the presence of inhibitors as E64 or leupeptin triggers a reversible conformational transition leading to a proper assembly of the active site without any aggregation or dissociation process. It is suggested that the observed conformational changes can be considered as the early step in the sequence of molecular events leading to calpain activation.
This report describes the scientific aims and potentials as well as the preliminary technical design of IRIDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity 'particle factory', based on a combination of a high duty cycle radio-frequency superconducting electron linac and of high energy lasers. Conceived to provide unique research possibilities for particle physics, for condensed matter physics, chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of science and technology. IRIDE will contribute to open new avenues of discoveries and to address most important riddles: What does matter consist of? What is the structure of proteins that have a fundamental role in life processes? What can we learn from protein structure to improve the treatment of diseases and to design more efficient drugs? But also how does an electronic chip behave under the effect of radiations? How can the heat flow in a large heat exchanger be optimized? The scientific potential of IRIDE is far reaching and justifies the construction of such a large facility in Italy in synergy with the national research institutes and companies and in the framework of the European and international research. It will impact also on R&D work for ILC, FEL, and will be complementarity to other large scale accelerator projects. IRIDE is also intended to be realized in subsequent stages of development depending on the assigned priorities.
Amine oxidases are a family of dimeric enzymes that contain one copper(II) ion and one 2,4,5-trihydroxyphenyalanine quinone per subunit. Here, the low-resolution structures of two Cu/TPQ amine oxidases from lentil ( Lens esculenta ) seedlings and from Euphorbia characias latex have been determined in solution by small-angle X-ray scattering. The active site of these enzymes is highly buried and requires a conformational change to allow substrate access. The study suggests that the funnel-shaped cavity located between the D3 and D4 domains is narrower within the crystal structure, whereas in solution the D3 domain could undergo movement resulting in a protein conformational change that is likely to lead to easier substrate access.
Abstract We investigated the cellular and molecular mechanisms by which bindarit, a small indazolic derivative with prominent anti-inflammatory effects, exerts its immunoregulatory activity in lipopolysaccharide (LPS) stimulated human monocytic cells. We found that bindarit differentially regulates the release of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1), enhancing the release of IL-8 and reducing that of MCP-1. These effects specifically required a functional interaction between bindarit and fatty acid binding protein 4 (FABP4), a lipid chaperone that couples intracellular lipid mediators to their biological targets and signaling pathways. We further demonstrated that bindarit can directly interact with FABP4 by increasing its expression and nuclear localization, thus impacting on peroxisome proliferator-activated receptor γ (PPARγ) and LPS-dependent kinase signaling. Taken together, these findings suggest a potential key-role of FABP4 in the immunomodulatory activity of bindarit, and extend the spectrum of its possible therapeutic applications to FABP4 modulation.
