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

Abstract

In this work, the interaction between nano-TiO(2) and trypsin was investigated, and the mechanisms of the interaction were explored by the methods of UV-vis detection, circular dichroism (CD), and fluorescence. The results clearly demonstrated that nano-TiO(2) had an inhibitory effect on the enzyme activity. The activity was decreased to 64% of the untreated trypsin in the presence of 300 μg/ml nano-TiO(2). UV spectrometry proved that nano-TiO(2) had a strong physical absorption effect on trypsin, and the CD spectra revealed that the secondary structure of trypsin was partly destroyed while bound together with nano-TiO(2). The ratio of α-helix increased from 7.9% to 12.8% in the presence of 100 μg/ml TiO(2) while the ratio of β-sheet decreased from 48.7% to 36.4%. Furthermore, the fluorescence spectrometry indicated that nano-TiO(2) could quench the intrinsic fluorescence of trypsin through static quenching. Meanwhile, the binding constant was calculated to be 1, and the process of binding of trypsin on nano-TiO(2) was a spontaneous molecular interaction procedure in which electrostatic interaction plays a major role. Our study was to provide a useful approach for evaluating the health risk of nanomaterials on level of proteins.

Size influences the cytotoxicity of poly (lactic-co-glycolic acid) (PLGA) and titanium dioxide (TiO2) nanoparticles

“…Some studies have reported that the interaction between nanoparticles and biomolecules could lead to dysfunction or damage of biomolecules (Deng et al 2011; Wang et al 2010; Shang et al 2007; Teichroeb et al 2008). Wang et al (2010) investigated the interaction between TiO 2 nanoparticles and trypsin. They observed a strong physical adsorption effect of TiO 2 nanoparticles on enzyme trypsin and found inhibitory effect of TiO 2 nanoparticles on trypsin activity by changing the α -helix and β -sheet ratio of the protein structure.…”

The Improvement of the Anticancer Effect of a Novel Compound Benzoic Acid, 2-Hydroxy-, 2-d-ribofuranosylhydrazide (BHR) Loaded in Solid Lipid Nanoparticles

“…In recent years, nanomaterials have been more frequently employed as vehicles for controlled drug delivery (6)(7)(8)(9)(10)(11)(12)(13). For instance, solid lipid nanoparticles (SLNs) have been introduced as an attractive alternative to traditional drug delivery systems (14)(15)(16)(17).…”

Systematic study on the influence of particle size on the Cytotoxicity of nanoparticles

“…Some studies have reported that the interaction between nanoparticles and biomolecules could lead to dysfunction or damage of biomolecules [108][109][110][111]. Wang et al [109] The data therefore suggests that the size dependent cytotoxicity of PLGA and TiO 2 nanoparticles should be related to different surface area of different-sized nanoparticles.…”

“…All the cytotoxicity studies showed that the cytotoxicity of Although it has been found that reaction between nanoparticles and proteins is related to some pathological changes such as protein aggregation or unfolding, the mechanism of these damages is still poorly investigated and understood [108]. Some studies have reported that the interaction between nanoparticles and biomolecules could lead to dysfunction or damage of biomolecules [108][109][110][111]. Wang et al [109] The data therefore suggests that the size dependent cytotoxicity of PLGA and TiO 2 nanoparticles should be related to different surface area of different-sized nanoparticles.…”

“…Others have reported that some pathological changes of proteins such as aggregation or unfolding of proteins after interaction with particles [88][89][90][91]. TiO 2 nanoparticles were reported to have strong adsorption effect on trypsin and can inhibit the activity of trypsin by changing α-helix and β-sheet ratio of the protein structure [109].…”