Carbonic anhydrase-magnetite nanocomposites with an RF field controlled enzymatic activity

Abstract

A magnetic enzymatic composite was synthesized from non-toxic magnetite nanoparticles modified by biomimetic polymerization of modified dopamine and carbonic anhydrase enzyme, which has a significant role in neurodegenerative processes. The mass fraction of the enzyme in the composite was 10% wt, which corresponded to about 120 enzyme molecules per nanoparticle. The composite showed Km about 10 folds higher compared to free enzyme (0.22 and 0.019 mmol/L respectively) and Vmax four times lower (0.17 and 0.69 mmol/min). The enzymatic composite had 17% higher thermal stability compared to free enzyme and retained 95% of its initial activity after seven consecutive reuse cycles. In a colloidal state, the composite showed no response to the RF field due to the ballistic mechanism of heat dissipation but in concentrated form, the material showed up to 155% enhanced catalytic activity under the influence of heating radio frequency magnetic fields. The observed results are discussed and explained.