“…For 40 years now, the 19 F atom has been exploited in biological NMR (Arseniev et al, 1986;Chaiken, Freedman, Lyerla, & Cohen, 1973), and several reviews have covered the field over the last two decades (Danielson & Falke, 1996;Didenko, Liu, Horst, Stevens, & Wüthrich, 2013;Gerig, 1994;Kitevski-Leblanc & Prosser, 2012;Marsh & Suzuki, 2014). Indeed, the 19 F atom has been used as a molecular probe to gain insight into protein and peptide structure (Danielson & Falke, 1996;Gerig, 1994;Kawahara et al, 2012;Liu, Horst, Katritch, Stevens, & Wuthrich, 2012), protein-ligand interactions (Campos-Olivas et al, 2002;Danielson & Falke, 1996;Gerig, 1994; Kitevski-Leblanc & Prosser, 2012;Luck & Falke, 1991;Rydzik et al, 2014), protein unfolding (Arseniev et al, 1986;Chaiken et al, 1973;Khan, Kuprov, Craggs, Hore, & Jackson, 2006;Kitevski-Leblanc, Hoang, Thach, Larda, & Prosser, 2013), protein aggregation (Danielson & Falke, 1996;Didenko et al, 2013;Gerig, 1994;Kitevski-Leblanc & Prosser, 2012;Li et al, 2009;Marsh & Suzuki, 2014;Suzuki, Brender, Hartman, Ramamoorthy, & Marsh, 2012), and protein dynamics (Fischer et al, 2003), clearly demonstrating the power and versatility of the fluorine probe for NMR.…”