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Nuclear magnetic resonance (NMR) is a powerful spectroscopic tool that can be used to study high-resolution structure and dynamics of biomolecular macromolecules using modern multi-dimensional pulse sequences. In particular, SSNMR has emerged as a powerful tool to study biological samples that do not tumble isotropically and cannot be easily crystallized such as amyloid fibrils, membrane proteins, and other large macromolecular complexes. In this thesis, solution NMR and solid-state NMR (SSNMR) experiments will be employed to study the slow dynamics of prion amyloid fibrils, the flexibility and ensemble preferences histone tails in a DNA-protein complex, and the structure of two covalent organic frameworks (COFs).Previous SSNMR results on fully protonated and uniformly labeled 13C-15N huPrP23-144 amyloid fibrils suggested that the ¿-rich 30 residue rigid core undergoes non-uniform 0.1-1.0 millisecond motion based on backbone 15N transverse relaxation rates at a slow magic-angle spinning (MAS) rate. To further investigate the presence and amplitude of slow motion in prion amyloid fibrils, a 50% back-exchanged perdeuterated sample was prepared in order to employ recently developed 1H-detected relaxation dispersion (RD) experiments at 40 kHz MAS. Low radio-frequency (RF) field 15N RD experiments (2-15 kHz) were combined with near rotary resonance dispersion (NERRD) experiments recorded near the n=1 rotary resonance condition (24-36 kHz) to accurately quantify the slow motional mode in huPrP amyloid fibrils. Numerical simulations of the entire 15N RF field range between 2 and 36 kHz fit best to a global exchange process occurring at 1 millisecond with a minor state population of 2%.Solution NMR experiments were used in these thesis to study the monomeric building block of chromatin, mononucleosomes, whereas SSNMR experiments were employed to study 17-mer nucleosomes arrays (in vitro mimic of chromatin). This work was all done in collaboration with Dr. Poirier at OSU in the Department of Physics. The mononucleosome is a protein-DNA complex that consists of ~ 147 bp of DNA that is wrapped around a histone octamer. The histone proteins in mononucleosomes are comprised of ~ 70-75% alpha-helical domains and 25-30% of unstructured, disordered tails. The overall hypothesis of our work herein is that the structure and flexibility of the disordered histone tails regulate chromatin’s structure and function. In my work, I present a suite of results from 15N relaxation experiments in mononucleosomes and 17-mer arrays in different compaction states to better understand their role in chromatin. Our main findings show the following: 1) H4 tails seem to be flexible than H3 tails; 2) Histone tails display a reduction in flexibility upon compaction, although they still remain flexible to allow for tightly controlled regulation; 3) H4(K16Q) histone tails display differences in flexibility in mononucleosomes and arrays although there is undoubtedly an increase in flexibility near the mutation site; and 4) H4 histone tails show a slight reduction in flexibility in extended arrays compared to mononucleosomes as a result of increased interaction with either linker DNA or adjacent nucleosomes. In addition to examining the flexibility of histone tails, I also investigated the structure of the H4 histone tail ensemble in mononucleosomes for the first time by using paramagnetic relaxation enhancement (PRE) experiments in solution. PRE experiments can probe distances on the 1.2 – 3.5 nm scale from differences in relaxation rates in a paramagnetic sample compared to a diamagnetic reference sample. These preliminary results seem to suggest that the histone H4 N-terminal tails exist in an ensemble that is exploring a vast amount of conformational space, which is in agreement with our 15N relaxation results. Further work and simulations will have to be done to accurately locate the histone H4 tail location and amount of space the tail occupies in mononucleosomes. In the last part of my PhD work, I was able to rapidly characterize and confirm the structure of two COFs in collaboration with Dr. McGrier at OSU in our department. These synthesized COFs were constructed with high surface areas and unique luminescence properties, which make them useful materials in possible sensory-based applications, storage and separations. I was able to confirm the structure of these materials by 13C cross-polarization MAS SSNMR experiments. In addition to using the general chemical shift trends, I was able to unambiguously assign all the 13C resonances in both COFs by employing novel 1H-13C dipolar recoupling experiments. In these experiments, 13C resonances were assigned based on local proximity to protons in the 2D framework. Most importantly, we were able to assign one alkynyl residue in the first COF and two alkynyl residues in the second COF.