不同粒径纳米颗粒对胰蛋白酶活性和空间构象的影响

he variations of conformation and enzyme activity of trypsin adsorbed on silica particles of various sizes (20 nm, 100 nm, 300 nm and amorphous level) had been studied. The adsorption amount of trypsin clearly decreased with the increase of silica particle size. The enzyme stability was strongly dependent on the size of the particles. Smaller silica particles enhanced trypsin stabilities in strongly denaturing environments to a greater extent than that of larger ones. When the silica-trypsin bioconjugates incubated at 80 ℃ for 1 h, the activity for trypsin adsorbed onto 20 nm, 100 nm, 300 nm and amorphous particles increased by 96.3%, 70.8%, 45.7% and 19.7% of its native activity, respectively. The effect of particle size on enzyme activity was depended on the change of enzyme structure after adsorption. And the fraction of activity lost correlated well with the increase of surface hydrophobicity, greater increase in surface hydrophobicity and lower retentive enzyme activity was observed for trypsin adsorbed onto larger nanoparticles under otherwise similar conditions.