The effect of functionalization of mesoporous silica nanoparticles on the interaction and stability of confined enzyme

چکیده مقاله

Immobilization of enzymes into the mesoporous nanomaterials results in formation of more stable and
even more active versions of biocatalysts. The effect of surface functionalization of mesoporous silica
nanoparticles (MSNs) on its adsorption characteristics and stability of superoxide dismutase (SOD) was
investigated. For this purpose, non-functionalized (KIT-6) and aminopropyl-functionalized cubic Ia3d
mesoporous silica ([n-PrNH2-KIT-6]) nanoparticles with 3-dimensional pores were used as supports. It
was observed that the amount of enzyme adsorbed on/within MSNs is dependent on the initial enzyme
concentration for both KIT-6 and [n-PrNH2-KIT-6] mesoporous silicas. However a stronger interaction
between SOD and [n-PrNH2-KIT-6] was observed relative to KIT-6. Increasing temperature favors a larger
amount of SOD immobilization into KIT-6, while it was negligible for [n-PrNH2-KIT-6]. Immobilized SOD
was more stable against urea and thermal denaturation relative to free enzyme and this improvement of
stability was more pronounced for SOD into the [n-PrNH2-KIT-6] than KIT-6. These results may be useful
in determining the mechanism(s) of protein immobilization and stabilization into the solid supports.