Myoglobin as a model for peroxidase enzyme by encapsulating it in a suitable reverse micelle
Encapsulation of proteins into micellar- like systems mimics the cell environment. Here, we introduce an approach for the encapsulation of a protein into a suitable reverse micelle which has much more benefits than in free aqueous medium in regard of the catalytic activity of the protein. The protein we dealt with in this study is horse heart Myoglobin. Using 2, 2- azino-bis (3-ethylbenzthiazoline-6-sulfate) (ABTS) as substrate, it has been found that the catalytic activity of Myoglobin is retained when encapsulated into a reverse micelle. It has been found that, there is no noticeable change in the secondary structure of Myoglobin when it is encapsulated into a suitable reverse micelle. The kinetic studies also revealed the catalytic activity of Myoglobin is much more pronounced in reverse micelle than in the aqueous medium. The reactant molecules are entrapped in a very specified area inside the water pool in the case of reverse micelle. The freedom of movement for reactant molecules in reverse micelle is very less compared to that in aqueous medium. Also, there is a hydrophobic crowding by the surfactant inside the reverse micelle which slightly exposes some part of the protein and makes the rate of reaction in reverse micelle more rapid compared to that in aqueous medium.
Keywords: myoglobin, reverse micelle, ABTS, hydrogen peroxide, pseudoperoxidase activity