Search

Your search keyword '"Iametti S"' showing total 258 results
Start Over Author "Iametti S"
258 results on '"Iametti S"'

17. Stabilization of beta-lactoglobulin by polyols and sugars against temperature-induced denaturation involves diverse and specific structural regions of the protein

Author

Barbiroli, A., Marengo, M., Fessas, D., Ragg, E., Renzetti, S., Bonomi, F., Iametti, S., Barbiroli, A., Marengo, M., Fessas, D., Ragg, E., Renzetti, S., Bonomi, F., and Iametti, S.

Abstract

Temperature sensitivity of bovine milk beta-lactoglobulin (BLG) was assessed in the presence/absence of non-reducing sugars (sucrose and trehalose) and polyols (glycerol and sorbitol). None of them affected the structural features of the protein at room temperature, where the only observed effect was an increased affinity towards hydrophobic probes in the presence of all co-solutes but glycerol. Although most of the observed effects in temperature-ramp experiments are due to entropic effects (fitting within the “preferential exclusion” theory of protein stabilization), this study indicates that each co-solute exhibit different efficacy at stabilizing specific regions of BLG, suggesting that each of them acts in a specific way on the solvent/protein system. The relevance of these observations with respect to systems of practical relevance is discussed, given the widespread use of heat-polymerizing proteins – such as BLG – in many food formulations that very often include significant amounts of sugars and/or polyols. © 2017 Elsevier Ltd

Published
2017

18. Unfolding of beta-lactoglobulin on the surface of polystyrene nanoparticles: experimental and computational approaches

Author

Miriani M, Eberini I, Iametti S, Sensi C, Bonomi F., FERRANTI, PASQUALE, Miriani, M, Eberini, I, Iametti, S, Ferranti, Pasquale, Sensi, C, and Bonomi, F.

Abstract

Structural changes ensuing from the non-covalent absorption of bovine beta-lactoglobulin (BLG) on the surface of polystyrene nanoparticles were investigated by using spectroscopic approaches, by assessing the reactivity of specific residues, and by limited proteolysis/mass spectrometry. Also, the immunoreactivity of absorbed and free BLG was compared. All these approaches indicated substantial rearrangements of the protein structure in the absorbed state, in spite of the reported structural rigidity of BLG. Changes made evident by experimental measurements were confirmed by computational approaches. These indicate that adsorption-related changes are most marked in the area between the main C-terminal alpha helix and the beta-barrel, and lead to full exposure of the thiol on Cys121 , consistent with experimental measurements. In the computational model of bound BLG, both Trp61 and Trp19 also move away from their neighboring quenchers and become solvent-exposed, as indicated by fluorescence measurement. Upon binding, the beta-barrel also loosens, with a substantial increase in immunoreactivity and with noticeable changes in the trypsinolytic pattern. The possible general significance of the structural changes reported here for non-covalently adsorbed BLG is discussed with respect to recognition events involving surface-bound proteins, as are aspects related to the carrier function(s) of BLG, and to its use as a common ingredient in many food systems.

Published
2014

19. The murein lytic enzyme TgaA of Bifidobacterium bifidum MIMBb75 modulates dendritic cell maturation through its CHAP amidase domain

Author

Guglielmetti, S, ZANONI, IVAN, Balzaretti, S, Miriani, M, Taverniti, V, De Noni, I, PRESTI, ILARIA, Stuknyte, M, Scarafoni, A, Arioli, S, Iametti, S, BONOMI, FEDERICA, Mora, D, Karp, M, GRANUCCI, FRANCESCA, Guglielmetti, S, Zanoni, I, Balzaretti, S, Miriani, M, Taverniti, V, De Noni, I, Presti, I, Stuknyte, M, Scarafoni, A, Arioli, S, Iametti, S, Bonomi, F, Mora, D, Karp, M, and Granucci, F

Subjects
bifidobacteriun bifidum, MED/04 - PATOLOGIA GENERALE
Abstract

Bifidobacteria are Gram-positive inhabitants of the human gastrointestinal tract that have evolved close interaction with their host and especially with the host's immune system. The molecular mechanisms underlying such interactions, however, are largely unidentified. In this study, we investigated the immunomodulatory potential of Bifidobacterium bifidum MIMBb75, a bacterium of human intestinal origin commercially used as a probiotic. Particularly, we focused our attention on TgaA, a protein expressed on the outer surface of MIMBb75's cells and homologous to other known bacterial immuno-active proteins. TgaA is a peptidoglycan lytic enzyme containing two active domains: Lytic murein Transglycosylase (LT) and Cysteine Histidine-dependent Amidohydrolase/Peptidase (CHAP). We ran immunological experiments stimulating dendritic cells (DCs) with the B. bifidum MIMBb75 and TgaA with the result that both the bacterium and the protein activated DCs and triggered interleukin (IL)-2 production. In addition, we observed that the heterologous expression of TgaA in Bifidobacterium longum transferred to the bacterium the ability to induce IL-2. Subsequently, immunological experiments performed using two purified recombinant proteins corresponding to the single domains LT and CHAP demonstrated that the CHAP domain is the immune-reactive region of TgaA. Finally, we also showed that TgaA-dependent activation of DCs requires the protein CD14, marginally involves TRIF, and is independent of TLR-4 and MyD88. In conclusion, our study suggests that the bacterial CHAP domain is a novel microbe-associated molecular pattern actively participating in the cross-talk mechanisms between bifidobacteria and the host's immune system

Published
2014

36. PEPTIDES AND PROTEINS IN BEERS: A PEPTIDOMIC APPROACH

Author

PICARIELLO G., NASI A., BONOMI F., IAMETTI S., FERRANTI, PASQUALE, PROF. MARTIN STERN, UNIVERSITY OG TUEBINGEN, GERMANY, Picariello, G., Ferranti, Pasquale, Nasi, A., Bonomi, F., and Iametti, S.

Published
2007

39. Molecular events during tendering of buffalo meat

Author

IAMETTI S., MORLEO A., BONOMI F., CAIRA S., GUALTIERI L., FERRANTI, PASQUALE, QUARTO, MARIA, CHIANESE, LINA, Iametti, S., Morleo, A., Bonomi, F., Caira, S., Ferranti, Pasquale, Quarto, Maria, Gualtieri, L., and Chianese, Lina

Published
2007

Catalog

Books, media, physical & digital resources
See catalog results