> Denaturing a protein generally requires a lot more .. than 100C

Nope. Protein generally denatures at lower than 100C / boiling point.

That's the principle of Sous Vide, not that you should use Sous Vide to sterilise anything, but the protein in egg white denatures at 60-80C.

http://www.scienceofcooking.com/eggs/eggs_sous_vide.htm

And in meat it's similar, 50-70C http://www.mpip-mainz.mpg.de/Sous_vide_cooking

If you doubt it, stick your hand in water at 80C and see what happens.

Prions don't degrade at the boiling point: http://www.microbiologyresearch.org/docserver/fulltext/jgv/8...

Sure, though that's entirely different from the grandparent post's statement about "Denaturing a protein generally", which happens well below boiling point.

Where did I claim they were rendered harmless at a mere 100C?