Do Peptide Bonds Break During Denaturation?

[Qube]

Homework Statement

Above 104°, these enzymes begin to lose their ability to catalyze reactions as they become denatured, that is, they lose their three-dimensional shape as hydrogen bonds and peptide bonds begin to break down.

Homework Equations

Peptide bonds DO NOT BREAK DOWN when proteins/enzymes are denatured. Peptide bonds form the primary structure of proteins and enzymes. All of the textbooks here are my sources:

https://www.google.com/search?q=pep...cp.r_qf.&fp=111e727753762aa8&biw=1366&bih=677

The Attempt at a Solution

Conclusion: the CliffNotes book is flat-out W R O N G.

Am I correct?

 

[chemisttree]

It would depend on how far above 104^oC one goes and how long it's held there but you are right that it is wrong for temperatures only somewhat above that temperature in a reasonable timeframe.

 

[Dave_Vader]

You are correct.
Trust me on this one. I'm doing a PhD in biochemistry.

Heard of the SDS-PAGE technique?
It involves heating proteins to 100C for 10 mins, and then running them on a gel.
I've run many, many gels, and my peptide-bonds have never broken.
You can make out by just looking at the stained-bands