NR AWMD
AU Polano,M.; Leita,L.; Negro,A.; Lamba,D.; Florio,T.; Corsaro,A.; De Nobili,M.
TI Environmental behaviour of prion proteins
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions RA-08
PT Konferenz-Poster
AB Before the risks connected to the past BSE epidemics were fully recognized, prions were discharged into the environment from rendering plants, abattoirs and landfills (Gale et al. 2001). Prions can still be occasionally dispersed through blood and even probably feces by infected animals and cause contamination of pastures and surface water (Belay et al. 2004). In this work we investigated the interactions among recumbinant murine (23-231) and human (90-231) prion proteins and environmental colloids. Recumbinant murine prion protein 23-231 was expressed in Escherichia coli cells cultures and purified according to the method described by Negro et al. (2000). Human 90-231 recumbinant prion protein was prepared as described by Corsaro et al. (2002). Interactions of prion proteins with humic substances in solution were investigated by differential UV spectroscopy. The first and second derivative were used to measure bathochromic effects and calculate exposure indexes. The relative contribution of the alpha-helixes, beta-sheets and random coil structures to the tertiary structure of the protein in solution was evaluated by circular dichroism before and after addition of humic and fulvic acids. Interaction between recombinant hamster or human prion proteins and humic acids in solution results in structural rearrangements of the proteins which affects side chains. Circular dichroism spectra confirmed the existence of interaction between the protein and show an increase in beta-sheet stucture for both proteins examined. Elaborations by the Autodock program coupled with experimental results suggest that the most probable sites of interaction are represented by the positively charged exposed groups of the histidine 115, the lysine 6 and arginine 79. Humic substances of both aquatic and terrestrial origin strongly interact with prion proteins and can therefore affect their behaviour in the environment.. These interactions together with those observed with clays explain the irreversible adsorption observed on soils rich in organic matter and clay and the lower affinity displayed by a sandy soil (Leita et al. in press). ACKNOWLEDGEMENTS This research was carried out within the RIFAFERT project funded by the Italian ministery of Agricultural and Forest Politics.
AD M. Polano, M. De Nobili: DiSAA, University of Udine, 33100 Udine, Italy; L. Leita: CRA, Istituto Sperimentale per la Nutrizione delle Piante, 34170 Gorizia, Italy; A. Negro: Centro Interdipartimentale di Ricerca e Servizi per le Biotecnologie Innovative (CRIBI) Università degli Studi di Padova, Italy; D. Lamba: Istituto di Cristallografia - C.N.R. Unità Staccata di Trieste (Elettra The Structural Biology Laboratory); T. Florio, A. Corsaro: Dipartimento di Oncologia, Biologia e Genetica Università di Genova, Italy. E-mail: denobili@uniud.it; maurizio.polano@uniud.it
SP englisch
PO Italien