Immobilization of His-tagged endoglucanase on gold via various Ni-NTA self-assembled monolayers and its hydrolytic activity

A genetically modified His-tagged endoglucanase, EGII(core2), with two active sites in series was immobilized on gold via three different kinds of anchor molecules, and its hydrolytic activity was studied. Immobilization of EGII(core2) was influenced by the chain length and hydrophilicity of anchor molecules. The hydrolytic activity of the immobilized EGII(core2) was nearly the same on either anchor molecule. Interestingly, the immobilized EGII(core2) apparently retained the inherent hydrolytic activity similarly to free EGII(core2). It is therefore considered that the local high concentration of EGII(core2) on the surface should promote the successive hydrolysis of the transient products to show the high hydrolytic activity despite of immobilization.