Functional Biomaterial Poly-γ-Glutamic Acid Designed for Thermostability of Zearalenone-Degraded

The influence of different additives (poly-γ-glutamic acid, polyethylene glycol) on the thermostabitity of zearalenone-degraded enzyme at 70°C has been studied in aqueous medium. The results obtained show a stabilizing effect in the presence of poly-γ-glutamic acid (ethylene glycol, glycerol, erythritol, xylitol, and sorbitol) and for most of the γ-PGA-PEG used. The influence of the monovalent ions on zearalenone-degraded enzyme thermostability can be correlated to the lyotropic series of Hofmeister.

Conformational changes in monolayers of a cationic amphiphilic porphyrin on saline subphases

Langmuir monolayer films of the tetracationic porphyrin tetrakis(octadecyl-4-pyridinium)porphyrinatozinc(II) bromide on various salt containing subphases were analyzed using surface pressure-area isotherms and X-ray reflectivity. The use of these complementary techniques showed that the porphyrin molecules undergo changes in conformation upon compression. Two main phases were identified, one in which the porphyrin moiety is parallel to the subphase and one in which the porphyrin moiety is tilted out of the plane. The addition of different salts into the subphase brought about changes in film behaviour, which are explained in terms of a lyotropic series.