This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Taking advantage of FPOP as a fast labeling strategy, we are building a two laser system that utilizes a Nd:YAG laser and a Raman shifter to quickly heat a protein, and then use the second laser to generate radicals to footprint the protein during unfolding. This method will allow us to probe protein dynamics on a microsecond time scale.