Stabilization of a pH-sensitive apoptosis-linked coiled coil through single point mutations
Open Access
- 1 February 2003
- journal article
- Published by Wiley in Protein Science
- Vol. 12 (2), 257-265
- https://doi.org/10.1110/ps.0223903
Abstract
The apoptosis-associated Par-4 protein has been implicated in cancers of the prostate, colon, and kidney, and in Alzheimer's and Huntington's diseases, among other neurodegenerative disorders. Previously, we have shown that a peptide from the Par-4 C-terminus, which is responsible for Par-4 self-association as well as interaction with all currently identified effector molecules, is natively unfolded at neutral pH, but forms a tightly associated coiled coil at acidic pH and low temperature. Here, we have alternately mutated the two acidic residues predicted to participate in repulsive electrostatic interactions at the coiled coil interhelical interface. Analysis of circular dichroism spectra reveals that a dramatic alteration of the folding/unfolding equilibrium of this peptide can be effected through directed-point mutagenesis, confirming that the two acidic residues are indeed key to the pH-dependent folding behavior of the Par-4 coiled coil, and further suggesting that alleviation of charge repulsion through exposure to either a low pH microenvironment or an electrostatically complementary environment may be necessary for efficient folding of the Par-4 C-terminus.Keywords
This publication has 24 references indexed in Scilit:
- pH‐induced folding of an apoptotic coiled coilProtein Science, 2001
- pH-induced folding of an apoptotic coiled coilProtein Science, 2001
- Interaction partners of Dlk/ZIP kinase: co-expression of Dlk/ZIP kinase and Par-4 results in cytoplasmic retention and apoptosisOncogene, 1999
- Evidence that Par-4 Participates in the Pathogenesis of HIV EncephalitisThe American Journal of Pathology, 1999
- Decreased expression of the pro-apoptotic protein Par-4 in renal cell carcinomaOncogene, 1999
- Inter-helical interactions in the leucine zipper coiled coil dimer: ph and salt dependence of coupling energy between charged amino acidsJournal of Molecular Biology, 1998
- Salt effects on protein stability: two-strandedα-helical coiled-coils containing inter- or intrahelical ion pairsJournal of Molecular Biology, 1997
- Thermodynamic Characterization of the Coupled Folding and Association of Heterodimeric Coiled Coils (Leucine Zippers)Journal of Molecular Biology, 1996
- The Effects of Interhelical Electrostatic Repulsions between Glutamic Acid Residues in Controlling the Dimerization and Stability of Two-stranded α-Helical Coiled-coilsPublished by Elsevier BV ,1995
- Determination of the helix and β form of proteins in aqueous solution by circular dichroismBiochemistry, 1974