Document Type

Article

Publication Date

2023

DOI

10.3390/biom13040667

Publication Title

Biomolecules

Volume

13

Issue

4

Pages

667 (1-15)

Abstract

Intrinsically disordered proteins play important roles in cell signaling, and dysregulation of these proteins is associated with several diseases. Prostate apoptosis response-4 (Par-4), an approximately 40 kilodalton proapoptotic tumor suppressor, is a predominantly intrinsically disordered protein whose downregulation has been observed in various cancers. The caspase-cleaved fragment of Par-4 (cl-Par-4) is active and plays a role in tumor suppression by inhibiting cell survival pathways. Here, we employed site-directed mutagenesis to create a cl-Par-4 point mutant (D313K). The expressed and purified D313K protein was characterized using biophysical techniques, and the results were compared to that of the wild-type (WT). We have previously demonstrated that WT cl-Par-4 attains a stable, compact, and helical conformation in the presence of a high level of salt at physiological pH. Here, we show that the D313K protein attains a similar conformation as the WT in the presence of salt, but at an approximately two times lower salt concentration. This establishes that the substitution of a basic residue for an acidic residue at position 313 alleviates inter-helical charge repulsion between dimer partners and helps to stabilize the structural conformation.

Rights

© 2023 by the Authors.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) License.

Data Availability

Article states: Not Applicable.

Original Publication Citation

Pandey, S., Raut, K. K., Clark, A. M., Baudin, A., Djemri, L., Libich, D. S., Ponniah, K., & Pascal, S. M. (2023). Enhancing the conformational stability of the cl-Par-4 tumor suppressor via site-directed mutagenesis. Biomolecules, 13(4), 1-15, Article 667. https://doi.org/10.3390/biom13040667

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