Maybe you want to denature a protein for a science project, or maybe you've read about denatured foods and want to know how they work. Denaturation is the process by which a protein loses its shape and structure due to the actions of external forces including heat, acids, and solvents. The exact way you denature a protein depends on the particular protein you want to work with, as they all require different denaturing agents at different levels. However, most proteins can be denatured if you know what to change in the environment of the protein.
Method 1 of 2: Denature a Protein
Step 1. Use the heat
Heat is one of the easiest and most common ways to denature a protein. When the protein in question is present in food, simply cooking the food will denature the proteins. Many proteins can be denatured when exposed to a temperature of 100 ° C (212 ° F) or higher. This allows proteins to clot and reduce their solubility.
The duration of exposure depends on what you expose to heat. An egg, for example, can be cooked in a skillet over medium heat in 5 minutes, while a roast meat can take hours to cook in an oven
Step 2. Apply rubbing alcohol
Alcohol breaks the hydrogen bonds that occur between amide groups. When a protein is exposed to an alcohol solution, the alcohol molecules form new bonds with the protein chain. Use a 70% alcohol solution to break down the bacteria cell wall and denature the protein.
Concentrated alcohols can be dangerous as they are flammable and toxic. Always wear full safety equipment, including gloves and eye protection, and handle them in a safe, temperature-controlled environment
Step 3. Change the pH
The internal structure of a protein can break down when its environment is very acidic or very alkaline, breaking the ionic bonds that hold the protein's salt bridges together. Add an acidic or basic solution to the protein. The environment must be at a pH greater than 10 or less than 4 to promote denaturation. If you are going to induce the change with acid, the pH should be between 2 and 5.
Changing the pH can ionize an amino acid, depending on the pKa of each functional group in that amino acid. It can also ionize the amino group or the carboxyl group present on the amino acid
Step 4. Try heavy metal salts
Heavy metals can alter the bonds in the protein, causing it to lose its structure. Heavy metal salts like mercury and lead can be used to denature various proteins. These salts are available from most chemical suppliers, and should always be used with caution and with the proper safety equipment, including gloves and eye protection.
Heavy metals can interact with functional groups on the side chain of a protein to form complexes. Heavy metals also oxidize the amino acid side chains of the protein
Method 2 of 2: Renature Proteins
Step 1. Determine if a protein can be refolded
Some forms of denaturation are permanent, while others can be undone. Cooking an egg or meat, for example, cannot be undone, but a protein that has been exposed to a high pH can regain its shape when placed in a more neutral environment.
Whether the protein can be refolded or not will depend on its DNA. The DNA will contain the information necessary for the protein to return to its native state
Step 2. Eliminate the denaturing factor
Returns the protein environment to stasis and removes the denaturing element. Remove the acid or base, for example, or reintroduce the protein at a more reasonable temperature.
Step 3. Use a renaturation kit
Many laboratory supply companies sell naturalization kits that allow you to select the best parameters to promote renaturation. These kits can be especially useful if you are working with proteins in a laboratory or experimental setting.