Quantification of HSP27 and HSP70 Molecular Chaperone Activities

Abstract

Stress-inducible heat-shock proteins (HSPs, like HSP70 and HSP27) are molecular chaperones that ­protect cells from stress damage by keeping cellular proteins in a folding competent state and preventing them from irreversible aggregation. HSP27 and HSP70 chaperone activities are useful indicators to test chemical products and physical stress impact on protein denaturation, to select HSP inhibitors, or to ­determine the implication of the chaperone function in other HSP activities, such as apoptosis. We have developed two simple and fast chaperone activity tests for HSP27 and HSP70 that we initially set up to test the effect of potential HSP inhibitors obtained after screening of chemical and small molecule libraries. These chaperone quantification tests are based on the capacity of HSP to counteract chemical or thermal protein aggregation.