... protein; GST, glutathione S-transferase;HD, Huntington’s disease; HIP1, Huntingtin interacting protein 1; HIPPI, Huntingtin interacting protein 1 protein interactor; Htt, Huntingtin;IOD, integrated ... decrease in the intrinsic fluorescence of GST–HIPPI protein, indica-ting binding of the protein with this mutated motif(Fig. 1B, panel II). The apparent dissociation constant(Kd) of this binding ... addition of the upstream sequences of the caspase-1 gene (717 bp) to the N-terminal domain (without the pDED domain) of HIPPI did notdecrease the fluorescence intensities determined byexciting either...