Denaturising Proteins: Mechanism & Effects Explained

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In summary, proteins denature when the temperature or pH rises above a certain point. This prevents the hypothalmus from controlling the body's temperature.
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FZ+
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Exactly what is the mechanism that makes proteins denature under certain conditions? (eg. too high temperature, pH etc etc) How does it all work?
 
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Proteins form as chains of peptides that fold up. Denturing the protein is the same as unfolding it.

The folds in the protein are held by electrostatic (i.e. Hydrogen) bonds, so increased pressure and temperature can provide sufficient free energy to knock the folding apart. The Ph can affect the relative electrostatic forces between the peptides and change the relative energy states of the protein.

Chemical and cold denaturing are probably more complicated.
 
  • #3
I hate to give you a link, but the topic of protein stability is not something which is easily broken down into a paragraph or two. It's a bit old, but still covers the essentials of the topic succinctly.

The Source of Stability in Proteins

In general, thermodynamics of the folded state versus the unfolded states will be a major determinant in whether or not a protein denatures. If one can overcome the hydrophobic interaction and various electrostatic/hydrogen bonding interactions, the protein will denature. The mechanism of cold denaturation has also been of increasing study, and a somewhat intuitive way to think about that is to consider that the colder the environment gets, the protein is sort of a "heat source" and it denatures as its energy is sucked out into the environment. This is hardly rigorous and even a bit misleading, and I would shudder at even describing it this way but it's not the easiest topic to describe in this sort of format. Chemical denaturation is typically taken to mean a reduction of a protein, where sulfide bridges are broken. While proteins can actually degrade via chemical methods, it's not the same as simply losing its fold. Detergents can also get a protein to unfold, surrounding hydrophobic regions with their long hydrocarbon tails and exposing their polar head group to the (typically) aqueous solvent.

The thing to remember is that protein folding is still something of a mystery - its reverse process is still something shaded in mystery, although we are gradually peeling back the veil.
 
  • #4
FZ+;
Let me first state that I'm no expert.

I'v been a paramedic for the last 28 years. Every year, we respond to two or three 'Heat Stroke' related calls. In my study of this contition, I have learned that when the internal body temperature raises above 105 dF, the protiens in the nerve tissue in the Hypothalmus, denature and permanently break down. This prevents the Hypothalmus (our internal thermostat) from nerologically doing it's job. This is serious because there is almost a 0% survivability rate with this.

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barry
 

1. What is protein denaturation?

Protein denaturation is a process in which the three-dimensional structure of a protein is disrupted, leading to a loss of its biological activity. This can be caused by various factors such as heat, pH changes, and exposure to chemicals.

2. How does denaturation affect the function of proteins?

Denaturation can affect the function of proteins by altering their shape, which is crucial for their specific functions. This can lead to a loss of enzymatic activity, binding ability, and other important biological functions.

3. What is the mechanism of protein denaturation?

The mechanism of protein denaturation involves the disruption of the non-covalent bonds and interactions that hold the protein's structure together. These include hydrogen bonds, disulfide bonds, and hydrophobic interactions. Once these bonds are broken, the protein loses its shape and function.

4. Can denatured proteins regain their structure and function?

In some cases, denatured proteins can regain their structure and function if the denaturing agent is removed. This process is called renaturation and it involves the reformation of the non-covalent bonds and interactions that hold the protein's structure together.

5. How does denaturation impact food and cooking?

Denaturation plays a crucial role in the cooking of food. Heat denatures proteins in food, which changes the texture and taste of the food. This is why cooked eggs are solid and have a different taste compared to raw eggs. Denaturation also increases the digestibility of proteins in food, making them easier to absorb and utilize by the body.

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