FAD binding overcomes defects in activity and stability displayed by cancer-associated variants of human NQO1

Angel L Pey, Clare F Megarity, David J Timson

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)
228 Downloads (Pure)

Abstract

NAD(P)H quinone oxidoreductase 1 is involved in antioxidant defence and protection from cancer, stabilizing the apoptosis regulator p53 towards degradation. Here, we studied the enzymological, biochemical and biophysical properties of two cancer-associated variants (p.R139W and p.P187S). Both variants (especially p.187S) have lower thermal stability and greater susceptibility to proteolysis compared to the wild-type. p.P187S also has reduced activity due to a lower binding affinity for the FAD cofactor as assessed by activity measurements and direct titrations. Native gel electrophoresis and dynamic light scattering also suggest that p.P187S has a higher tendency to populate unfolded states under native conditions. Detailed thermal stability studies showed that all variants irreversibly denature causing dimer dissociation, while addition of FAD restores the stability of the polymorphic forms to wild-type levels. The kinetic destabilization induced by polymorphisms as well as the kinetic protection exerted by FAD was confirmed by measuring denaturation kinetics at temperatures close to physiological. Our data suggest that the main molecular mechanisms associated with these cancer-related variants are their low binding affinity for FAD and/or kinetic instability. Thus, pharmacological chaperones may be useful in the treatment of patients bearing these polymorphisms.
Original languageEnglish
Pages (from-to)2163-2173
Number of pages11
JournalBiochimica et biophysica acta
Volume1842
Issue number11
DOIs
Publication statusPublished - Nov 2014

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Fingerprint Dive into the research topics of 'FAD binding overcomes defects in activity and stability displayed by cancer-associated variants of human NQO1'. Together they form a unique fingerprint.

Cite this