Question

In the 1950s, Christian Anfinsen demonstrated the renaturation of the protein ribonuclease (RNase) in vitro. After reduction and the addition of urea, the protein was in an unfolded state. After removing the urea and then the reducing agent, the protein oxidized and refolded, with greater than 90% activity. If reducing agent removal occurs before removing the urea, the protein showed less than 5% activity. Why does synthetically produced RNase refold incorrectly if the reducing agent is removed before urea removal? Contaminants in the RNase preparation would form covalent bonds with the protein, preventing reactivation. Urea would participate in weak bonding interactions with RNase, preventing oxidation of Cys. Disulfide bonds are not positioned correctly unless weak bonding interactions are present. The protein would not fully denature.

Answer 1

Answer and Explanation:

The basic synthetic denaturant of proteins is urea. The high convergence of urea causes unfolding of protein and in this way brings about loss of capacity of protein. The urea collaborates with the protein and averts collapsing of protein.

During oxidation, the disulfide bonds that are required for appropriate working and adjustment of protein are shaped, while in nearness of urea, the disulfide bonds are not situated accurately. The protein oxidation brings about covalent alteration of protein that outcomes in change of physical and synthetic properties of protein.

The difference in physical and synthetic properties of protein after oxidation and in nearness of urea can't be adjusted even after expulsion of urea. In this manner, protein doesn't overlap appropriately.