The selective modification of amino acids within proteins represents the epitome of a chemoselective reaction. Current protein modification techniques are constrained to nucleophilic and redox-active residues, restricting their ability to target amino acids outside this scope. Herein, we introduce the method for selectively modifying Asparagine and Glutamine in proteins that have never been targeted before via unorthodox isohypsic reaction to bioorthogonal nitrile handles under physiological conditions. This methodology not only expands the scope of protein modification but also unveils new, ligandable sites across the human proteome through comprehensive chemoproteomic profiling. Additionally, the isohypsic dehydration reaction has been effectively employed to profile deamidation and N-glycosylation post-translational modifications on Asparagine and Glutamine, leading to the identification of previously unknown deamidation sites and significant alterations in N-glycosylation events linked to disease processes. This research offers a transformative approach with profound implications for protein engineering and understanding disease mechanisms.