Publications by authors named "Luciano H di Stefano"
Article Synopsis
- The LINE-1 retrotransposon is a significant genetic element in humans, contributing to about a third of our genome via a 'copy and paste' method driven by its enzyme, ORF2p, which is linked to diseases like cancer and autoimmunity.
- Recent studies using X-ray crystallography and cryo-electron microscopy have revealed new structural details of ORF2p, including previously unknown domains and a dynamic conformation that changes during the retrotransposition process.
- The findings enhance our understanding of L1 replication and its effects on immune responses, creating potential pathways for drug development targeting L1 and related cellular processes.
Article Synopsis
- LINE-1 (L1) retrotransposons create diverse ribonucleoproteins (RNPs) during their replication and the host's efforts to limit them, but their exact makeup is still not well understood.
- The composition of L1-associated macromolecules varies according to factors like the L1 life cycle stage, whether it’s dealt with productively or suppressed, and the specific cell type involved.
- This chapter presents techniques for identifying and analyzing the protein and RNA components of L1 macromolecules from tissues, using embryonal carcinoma cell lines (like N2102Ep) and colorectal cancer tissues as primary examples.
Article Synopsis
- * Targeting ATM, ATR, or DNA topoisomerases can cause significant aggregation of proteins, particularly those prone to aggregation such as Huntingtin with an expanded polyglutamine repeat, due to a breakdown in cellular chaperone systems.
- * Inhibition of the HSP70 chaperone system worsens protein aggregation, while the chaperone HSPB5 can help suppress this aggregation, indicating a connection between genotoxic stress and protein aggregation similar to conditions seen in protein-related diseases.
Fast photochemical oxidation of proteins (FPOP) is a MS-based method that has proved useful in studies of protein structures, interactions, conformations, and protein folding. The success of this method relies on the irreversible labeling of solvent-exposed amino acid side chains by hydroxyl radicals. FPOP generates these radicals through laser-induced photolysis of hydrogen peroxide.
View Article and Find Full Text PDFDespite significant affinity to carbonyl oxygens, thermal hydrogen atoms attach to unmodified polypeptides at a very low rate, while the hydrogen-hydrogen exchange rate is high. Here, using the novel omnitrap setup, we found that attachment to polypeptides is much more facile when radical site is already present, but the rate decreases for larger radical ions. The likely explanation is the intramolecular hydrogen atom rearrangement in hydrogen-deficient radicals to a more stable or less accessible site.
View Article and Find Full Text PDFIn this paper, the first study of cationic cyanine dye Astrazon Orange-R by combined spectroscopic and theoretical investigation is presented. It is shown that molecular modeling of Astrazon Orange-R is in very good agreement with experiment, allowing us to gain insight into its complicated photophysics. A solvent viscosity controlled relaxation of excited states, involving cyanine isomerization, is also outlined.
View Article and Find Full Text PDFThe combination of a dye which absorbs the photon, an electron acceptor and an electron donor leading to energy conversion through electron transfer, was the basis of the so called three-component systems. In this paper, an experimental work combining Rose bengal dye with a triazine derivative as electron acceptor and ethyl 4-(dimethylamino)benzoate as electron donor, will underline the benefit of the photocyclic behavior of three-component systems leading to the dye regeneration. A thermodynamic approach of the photocycle is presented, followed by a mechanistic and computational study of ideal photocycles, in order to outline the specific kinetics occuring in so called photocatalytic systems.
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