> Amino acid sequences are just a bunch of jumbled words if you compared them to English. It usually has to go through folding to form proper "sentences" with meanings. I guess you can compare this to "grammar".

Thanks for a very informative comment! Would you have a minute to give a concrete example of such a sentence (something that could be in a training set)? Whenever I add "folding" to queries containing a variation of amino acids, Google starts showing images instead of sequences. (I have no background in bioinformatics.)