Structural biology as a field has advanced immensely in the last few years, but the mechanistic roles of protein disordered regions and their associated post-translational modifications on the molecular level are still poorly understood. Nuclear magnetic resonance offers the possibility to investigate these regions with atomic resolution and understand the effect of protein modification, and thus protein regulation. However, obtaining suitable and well-defined samples is not straightforward. Here, I review some approaches to protein semi-synthesis for nuclear magnetic resonance purposes, and their applications. I hope to demonstrate that these chemical and structural biology techniques create a powerful synergy that enables structural studies of protein regulation.