Effects of nano-sized silicon dioxide on the structures and activities of three functional proteins

Graphene oxide derivatives with variable alkyl chain length and terminal functional groups as supports for stabilization of cytochrome c

“…Non covalent immobilization Covalent immobilization activity of cyt c decreased up to 50% upon its immobilization onto GBNs compared to that of free cyt c (data not shown), which is in accordance to that observed when other nanomaterials that have been used as nanosupports [39]. The reduced peroxidase activity of the immobilized cyt c could be attributed to structural changes on the protein molecule due to interactions with GONs [20].…”

“…Alpha-helical content decreases from 34% to 26% and 28.5% for non covalently and covalently immobilized cyt c respectively, while the ␤-sheet content increases from 17.5% up to 30 and 32% for non covalently and covalently immobilized cyt c respectively. Similar structural changes have been previously reported for cyt c after its immobilization on multi-walled carbon nanotubes [46], nano-SiO2 particles [39] or hydrogen titanate nanotubes [47]. Moreover, cyt c seems to preserve more its secondary structure after immobilization on most GONs compared to porous and non-porous nanozeolites, where the ␣-helical content of cyt c is decreased in a higher extent [48].…”

High-throughput, quantitative assessment of the effects of low-dose silica nanoparticles on lung cells: Grasping complex toxicity with a great depth of field

“…Of the amorphous silicas examined, AERO-SIL® 200 induced the most severe changes in the lungs of rats, which only partly recovered. Previous in vitro studies also showed that amorphous silica nanoparticles were toxic to lung cells [4,6,7].…”

The Electrostatic Interactions Between Nano-TiO2 and Trypsin Inhibit the Enzyme Activity and Change the Secondary Structure of Trypsin

“…The similar phenomenon was also observed in previous studies. Xu and colleagues showed that DNase II undergo a reduction in both β-sheet content and enzymatic activity when absorbed on nano-SiO 2 [25]. Nanoparticles provided larger surface area of contact for adsorbed proteins which results in stronger interactions between proteins and nanoparticles.…”