Mohammed Sabbah, Prospero Di Pierro, C. Valeria L. Giosafatto, Marilena Esposito, Loredana Mariniello, Carlos Regalado-Gonzales and Raffaele Porta
الملخص العربي
Zeta potential and nanoparticle size were determined on film forming solutions of nativeand heat-denatured proteins of bitter vetch as a function of pH and of different concentrations of thepolyamines spermidine and spermine, both in the absence and presence of the plasticizer glycerol.Our results showed that both polyamines decreased the negative zeta potential of all samples underpH 8.0 as a consequence of their ionic interaction with proteins. At the same time, they enhanced thedimension of nanoparticles under pH 8.0 as a result of macromolecular aggregations. By using nativeprotein solutions, handleable films were obtained only from samples containing either a minimum of33 mM glycerol or 4 mM spermidine, or both compounds together at lower glycerol concentrations.However, 2 mM spermidine was sufficient to obtain handleable film by using heat-treated sampleswithout glycerol. Conversely, brittle materials were obtained by spermine alone, thus indicating thatonly spermidine was able to act as an ionic plasticizer. Lastly, both polyamines, mainly spermine,were found able to act as “glycerol-like” plasticizers at concentrations higher than 5 mM underexperimental conditions at which their amino groups are undissociated. Our findings open newperspectives in obtaining protein-based films by using aliphatic polycations as components
دكتور. محمد صباح | Dr. Mohammed Sabbah | 5448