Layered structural heme protein magadiite nanocomposites with high enzyme-like peroxidase activity

Layered nanocomposites of global myoglobin (Mb)-magadiite and hemoglobin (Hb)-magadiite with the interlayer distances of 43.2 and 68.2 Angstrom, respectively, have been successfully prepared by using tetrabutylammonium (TBA)-magadiite as the intermediate under mild conditions. The structures, details of the interaction between the host magadiite and guest proteins, and saturated bounding amounts of Mb and Hb were characterized and studied by many techniques. The enzyme activity study showed that the fresh intercalated Mb and Hb nanocomposites retained most enzyme-like peroxidase activity and about 25.0% of activities based on the formation amounts of tetramers were kept after 30 min of reaction when these nanocomposites were stored for 1 month at room temperature. The relations between the structures and the peroxidase activities were discussed based on Michaelis-Menten model analyses. Such stable and high enzyme-like peroxidase activity for immobilized Hb and Mb provide potential application in biosensors and enzyme reactors.