In many viruses and phages, scaffolding proteins (SPs) are required to ensure the correct organization of coat proteins (CPs) and other minor capsid proteins into a precursor structure, called a procapsid [428,429]. Although SPs are critical for viral assembly and therefore potential therapeutic targets their structural properties (with only a few exceptions [430,431]) are poorly understood. The size limitation of NMR can be used advantageously as a filter to identify disordered segments even in very large supramolecular protein complexes. In this way, NMR can provide a unique perspective on the dynamic and disordered elements of macromolecules not accessible by other techniques. The procapsid encapsulation experiments described by Whitehead et al. [432] were conceptually analogous to in-cell NMR experiments [433,434,435] in which signals from small proteins, or flexible segments of proteins, can be observed when they are incorporated inside living cells, as long as the isotope-labeled proteins of interest do not interact strongly with other large cellular components [433,434,435]. The so called ‘‘in-virus’’ NMR strategy applied by Whitehead et al. [432] could be more generally used to study the dynamic properties of macromolecules encapsulated into virus particles, including cargo molecules encased in viral capsids for nanotechnology applications. Additionally, such studies could assess the level of interaction of cargo molecules with the virus and probe the release properties of cargo NMR [432].