I just downloaded this and it's going on my desktop right now (if I ever close it).
What is it? It's a really simple little program that will tell you what protease (trypsin, lysC, etc., etc., it has everything I can think of preloaded) is a good decision for your experiment and what you're trying to accomplish!
There probably aren't too many proteins that people on this planet have spent more money studying than KRAS --
I highlighted the part that everyone I've ever met seems to care about. Trypsin ain't gonna do it. What will?
You could sit there with a calculator and look at what the 7 different enzymes you have sitting around from past experiments might do -- or -- you could load your FASTA (with isoforms, etc, heck -- your ENTIRE ORGANISM FASTA) -- and just pick from an amazing array of digestion conditions
(This thing is super easy to use, you don't need instructions if you're a lazy person)
And -- we have a winner! AspN (with considering up to 2 missed cleavage) totally covers the whole lysine rich domain.
Worth noting, there are other helpful tools here including handy histograms to visualize theoretical output.
Don't feel like reading more than this? You can download this great piece of software at Github here.