Structure-function relationships in solvatochromic fluorophores targeting human and bovine carbonic anhydrases.

The development of reversible, selective, small molecule fluorescent probes displaying high fluorescence turn-on responses and tight binding affinity with specific metalloenzymes requires consideration of multiple factors. In this study, we report a library of fluorescent probes for two carbonic anhydrases: human carbonic anhydrase II (hCAII) and bovine carbonic anhydrase II (bCAII) and compare differences in fluorescence turn-on and binding affinity with molecular docking to gain insight into structure-function relationships. We analyze the roles of electrostatics, hydrophobics, and sterics in influencing the fluorescence response of the probes with hCAII and bCAII which have 80 % sequence identity but drastically different fluorescence turn-on values with amino(na)phthalimide-based fluorophores.