As part of our goal to generate triggers of protein conformational changes, femtosecond laser pulses at 270nm, the Tisapphire 3rd harmonic, are utilized to break S-S bonds we studied small helix bundles that are constrained to be non-helical as a result of the disulfide bridge. The resulting processes involve helix formation and geminate recombination of the sulfhydryl radicals. Both are interesting since they are controlled by the fluctuations of the protein atoms. This project involves a new technology of ultraviolet pumping and infrared probing of protein dynamics. These studies of these systems on a femtosecond timescale have lent a valuable insight into the processes surrounding their geminate recombination. As an extension of these experiments, we have developed technologies to probe the dynamics of these peptides over 8 orders of magnitude in time out to the ms time scale. The effect of temperature and alpha helix promoting solvents (such as trifluoro ethanol) are now being investigated on the kinetics of these systems.
Showing the most recent 10 out of 128 publications