Fluorescence studies of small heat shock protein oligomerization

Small heat shock proteins (sHSPs) act as chaperone molecules, capable of preventing the unfolding and subsequent irreversible aggregation of target proteins. Regulation of sHSP chaperone function is tied to their oligomeric aggregation state, which ranges from small but active monomers and dimers to large, but mostly dormant, complexes consisting of 24 or more subunits. This range of complexes, or "oligomeric equilibrium", is influenced by environmental factors like temperature or pH. The project described in this poster uses various fluorescence methods to investigate the oligomeric equilibrium for the protein MjHSP16.5. Complexes formed from fluorescently labelled MjHSP16.5 samples are characterized individually through confocal microscopy. Samples that have been exposed to low pH and/or high temperature fluoresce less than untampered complexes, consistent with a shift toward smaller complexes in response to extreme conditions. The results of this experiment will be presented and compared with partnering experiments that examine MjHSP16.5 samples in dilute solutions through fluorescence correlation spectroscopy or in concentrated solutions though bulk FRET measurements.