Enzymatic hydrolysis of a layer-by-layer assembly prepared from chitosan and dextran sulfate

The specific enzymatic hydrolysis of an LbL assembly prepared from chitosan and dextran sulfate was quantitatively analyzed using a quartz crystal microbalance (QCM). It was found that the LbL assembly with the outermost surface with a charge opposite to the net charge of the enzyme was preferentially hydrolyzed compared to a surface with the same charge as the enzyme, possible due to the electrostatic condensation of the enzyme, even when the polymer substrate lies under the surface layer of the LbL assembly. In other words, when an enzyme shows electrostatic repulsion against its polymer substrate, construction of an LbL assembly will facilitate rapid hydrolysis of the polymer.