“…For the purpose of this study, we employed a comprehensive high definition mass spectrometry (HDMS E ) approach to investigate the venom from ten species of an arboreal tarantula commonly known as the "tiger" or "ornamental" spider (Genus Poecilotheria): P. striata, P. regalis, P. rufilata, P. formosa, P. metallica, P. miranda, P. tigrinawesseli, P. fasciata, P. ornata, P. smithi, and P. vittata. While there have been studies of whole venom from this genus of aggressive tarantula [46][47][48][49], our laboratory is the first to characterize a complete primary structure of a poecilotheriatoxin as well as evaluate the impact isomerization has on a toxin's physiological effect(s). Using a combination of digestion strategies, fragmentation techniques, and tandem high-resolution ion mobility spectrometry (IMS-interchangeable in this manuscript as high definition mass spectrometry HDMS E ), potential candidates for one non-enzymatic PTM was identified and confirmed, i.e., isomerization of Asp.…”