Nanogelation and Thermal Stabilization of Enzyme by Vitamin B6‑Bearing Polysaccharide as Biocrosslinker

Nanogels containing a protein (carbonic anhydrase, CA) were prepared by cross-linking CA and pyridoxal (vitamin B6)-bearing pullulan (PLPP) as a biocrosslinker via Schiff base formation. UV titration and high-performance liquid chromatography confirmed that CA was quantitatively complexed with PLPP in the presence of zinc ions. Dynamic light scattering and transmission electron microscopy showed that the nanogel diameter was about 20 nm. CA retained 90% of its native activity after complexation with PLPP. Moreover, the residual enzymatic activity of CA after heating and its long-term storage stability at room temperature were improved by complexation with PLPP. Enzyme nanogelation with PLPP is an efficient method for enzyme stabilization.