The Effects of the Metal Ion Substitution into the Active Site of Metalloenzymes: A Theoretical Insight on Some Selected Cases

A large number of enzymes need a metal ion to express their catalytic activity. Among the different roles that metal ions can play in the catalytic event, the most common are their ability to orient the substrate correctly for the reaction, to exchange electrons in redox reactions, to stabilize negative charges. In many reactions catalyzed by metal ions, they behave like the proton, essentially as Lewis acids but are often more effective than the proton because they can be present at high concentrations at neutral pH. In an attempt to adapt to drastic environmental conditions, enzymes can take advantage of the presence of many metal species in addition to those defined as native and still be active. In fact, today we know enzymes that contain essential bulk, trace, and ultra-trace elements. In this work, we report theoretical results obtained for three different enzymes each of which contains different metal ions, trying to highlight any differences in their working mechanism as a function of the replacement of the metal center at the active site

Oenin and Quercetin Copigmentation: Highlights From Density Functional Theory

Making use of anthocyanin copigmentation, it is possible to effectively improve color quality and stability of red wines and other foods. This can be done by selecting strong copigments, but a 1-fold experimental screening usually entails a high cost and a low efficiency. The aim of this work is to show how a theoretical model based on density functional theory can be useful for an accurate and rapid prediction of copigmentation ability of a copigment. The present study, concerning the copigmentation between oenin and quercetin under the framework of implicit solvent, indicates that, in these conditions, the intermolecular hydrogen bonds play an important role in the system stabilization. The dispersion interaction slightly affects the structure, energies and UV-Vis spectral properties of the copigmentation complex

Can BODIPY Dimers Act as Photosensitizers in Photodynamic Therapy? A Theoretical Prediction

The photophysical properties of some monomeric and dimeric BODIPY systems were investigated at the density functional theory level and herein reported. In particular, the absorption spectra were fully characterized, low energy singlet and triplet excited states were discussed also focusing on the energy difference gaps between them and computing the spin-orbit couplings values for the possible intersystem crossing channels. The heavy atom effect of iodine substituents on the photophysical properties of a monomer and on a dimer under investigation was also estimated. Results obtained on the considered compounds allow us to predict which is the most promising candidate to be suggested as a photosensitizer in photodynamic therapy

Investigazione teorica delle proprietà delle unità strutturali presenti negli acidi nucleici e delle interazioni di queste con ioni metallici e molecole di acqua

Dottorato di Ricerca in Metodologie Chimiche Inorganiche,XX Ciclo,a.a. 2006-2007Università della Calabri

Determinadi meccanismi di reazioni catalizzate da metallo-enzimi

Dottorato di Ricerca in Metodologie Chimiche Inorganiche,XXIII Ciclo,a.a.2009-2010Università della Calabri

Strategie di Attivazione di Molecole Attraverso l’Uso di Catalizzatori Metallici

Dottorato di Ricerca in Metodologie Chimiche Inorganiche,XX Ciclo,a.a. 2006-2007Università della Calabri