Andrei Tokmakoff

Tokmakoff is a principal developer of 2-dimensional time-resolved infrared spectroscopy (2D IR) and related techniques. Using them, he studies water dynamics, protein unfolding, proton transfers, protein-protein dissociation and DNA melting. He showed how combining rephasing and non-rephasing signals yields the 2D IR spectrum. His three-pulse echo peak shift study of water dynamics provided the first experimental evidence for temporal evolution of hydrogen bond stretching, and for structural relaxation on the 1.5 ps time scale. He spearheaded 2D IR elucidation of protein conformation and secondary structure, including demonstrating the role of self-assembly of soft nanotubes in light-harvesting organisms via an exciton mechanism, and of how specific tautomers of the anti-HIV agent KP1212, among several that isomerize in sub-picoseconds, induce mutations in the HIV virus and hence its therapeutic activity.