(First, been reading this place for a while but just now registering and posting. Hi!)
I'm going to build on what someone said before... saving "proteins" isn't what matters here. You mentioned that you're on a new diet. From a biochemical perspective, then, what you're interested in is actually amino acids. Amino acids are the monomer building blocks of proteins and serve two basic dietary functions -- they can be oxidized for energy or used to support or promote lean mass (especially muscle). Carbohydrate and fat are better at the first, so even if you are following an absurdly low-carb diet like Atkins, the calories from protein for energetic metabolism are going a non-factor because you'll get it from fat. That means you're looking at muscle, and muscle tissue actually absorbs amino acids rather than (large) proteins.
If I went into the laboratory right now and wanted to break up a protein, I'd put it in a low pH (highly acid) fluid at an elevated temperature. That sounds a lot like a stomach. If I wanted to degrade it further, I might throw a lot of enzymes at it to break even more bonds, and this sounds a lot like the pancreas. By the time the food is absorbed by your intestine, it's mostly in very short chained peptides or even individual amino acids.
So, unless you're burning the **** out of your food so that all of it is a black, sooty mass, then don't worry about cooking degrading protein. Your body knows how to deal with it.