Dr. Radić is a graduate of the University of Zagreb in Croatia where he started his research in acetylcholinesterase (AChE) reaction kinetics under mentorship of late Dr. Elsa Reiner, one of founding contributors in the field of cholinesterases. His interests in the AChE molecular structure brought him to the laboratory of Dr. Palmer Taylor at UCSD where he provided key contributions to functional mapping of the AChE molecule using site directed mutagenesis and defined structural domains and amino acid residues critical for catalytic activity and ligand interaction. He was the first to propose common, simplified kinetic scheme and equation to describe acetylcholine (ACh) turnover by both AChE and its structurally and functionally close relative butyrylcholinesterase (BChE) that included both substrate inhibition of AChE and substrate activation of BChE, two prominent forms of deviation from Michaelis-Menten kinetcs. Later this scheme and mechanism proved useful for the description of oxime reactivation kinetics of nerve agent organophosphate (OP) and OP pesticide conjugated AChE and BChE including positive allosteric modulation in reactivation of OP-BChE and negative allosteric modulation of OP-AChE conjugates. Dr. Radić developed intrinsic tryptophane fluorescence based assays as a highly valuable tool for in vitro monitoring of time resolved and equilibrium interactions of cholinergic ligands with native nicotinic acetylcholine receptor ligand binding domain surrogates, ACh binding proteins (AChBPs), as well as with AChE and BChE. This assay proved essential in functional characterization of one of tightest known, high affinity binding small molecule femtomolar AChE inhibitors developed in collaboration with Dr. Barry Sharpless of The Scripps Research Institute in La Jolla (TSRI). Dr. Radić leads, as a PI, NIH funded international collaborative project with researchers from TSRI (Dr. Barry K. Sharpless and Dr. Valery Fokin) and Institute for Medical Research and Occupational Health in Zagreb, Croatia (Dr. Zrinka Kovarik) towards development of novel, improved oxime reactivators of OP-AChE and OP-BChE conjugates, both in vitro and in vivo.