University of Cagliari

About: University of Cagliari is a education organization based out in Cagliari, Italy. It is known for research contribution in the topics: Population & Dopamine. The organization has 11029 authors who have published 29046 publications receiving 771023 citations. The organization is also known as: Università degli Studi di Cagliari & Universita degli Studi di Cagliari.

Observation of J/psi phi Structures Consistent with Exotic States from Amplitude Analysis of B+ -> J/psi phi K+ Decays

Abstract: The first full amplitude analysis of B+→J/ψϕK+ with J/ψ→μ+μ−, ϕ→K+K− decays is performed with a data sample of 3 fb−1 of pp collision data collected at s√=7 and 8 TeV with the LHCb detector. The data cannot be described by a model that contains only excited kaon states decaying into ϕK+, and four J/ψϕ structures are observed, each with significance over 5 standard deviations. The quantum numbers of these structures are determined with significance of at least 4 standard deviations. The lightest is best described as a D±sD∗∓s cusp, but a resonant interpretation is also possible with mass consistent with, but width much larger than, previous measurements of the claimed X(4140) state.

Multidrug binding properties of the AcrB efflux pump characterized by molecular dynamics simulations

Abstract: Multidrug resistance in Gram-negative bacteria, to which multidrug efflux pumps such as the AcrB transporter makes a major contribution, is becoming a major public health problem Unfortunately only a few compounds have been cocrystallized with AcrB, and thus computational approaches are essential in elucidating the interaction between diverse ligands and the pump protein We used molecular dynamics simulation to examine the binding of nine substrates, two inhibitors, and two nonsubstrates to the distal binding pocket of AcrB, identified earlier by X-ray crystallography This approach gave us more realistic views of the binding than the previously used docking approach, as the explicit water molecules contributed to the process and the flexible binding site was often seen to undergo large structural changes We analyzed the interaction in detail in terms of the binding energy, hydrophobic surface-matching, and the residues involved in the process We found that all substrates tested bound to the pocket, whereas the binding to this site was not preferred for the nonsubstrates Interestingly, both inhibitors [Phe-Arg-β-naphthylamide and 1-(1-naphtylmethyl)-piperazine] tended to move out of the pocket at least partially, getting into contact with a glycine-rich loop that separates the distal pocket from the more proximal region of the protein and is thought to control the access of substrates to the distal pocket