Abstract: NMR spectroscopy has been instrumental in solving the structure and probing thedynamics of biomolecules over a wide range of timescales. In NMR, the through-spaceand through-bond interactions between nuclear spins are exploited to transfermagnetization, from which structural information like internuclear distances and dihedralangles can be derived. However, internuclear distances greater than 5-6 Å are notmeasurable using these traditional approaches.Introduction of an unpaired electron spin in the vicinity of nuclear spins results inparamagnetic shifts and relaxation enhancement (PRE) which are measurable by NMR.The observed effect depends on the properties of the unpaired electron. In this talk, we willfocus exclusively on PRE effects induced by unpaired electrons, with an isotropic g-tensor, which result in small to negligible paramagnetic shifts. We will discuss PRE-derivedNMR restraints and recent applications to structure determination/refinement and dynamics of biomolecules in solution.