i have often wonderd what the damage to an amino acid chain would be under intense heat, although the research i did was inclusive, (as the pros and cons kinda balanced)
you have to ask yourself, how would protein bars be viable if protein would not tolerate heat, and also how would the amino acid chains in say beef or chicken survive when subjected to the high heat of a grill or oven?
One thing i did pick up from my research, and later on from a former gold medalist weight lifter and now nutritionist is that nearly all macronutrient enzymes are in some way compromised at heats in excess of 160 degrees C.
So i apply that to all of my food prep now, never subjecting food to over said amount.
However, i am currently very low carb so the above may sound like the ramblings of a madman 