Protein folding stabilities are a major determinant of oxidation rates for buried methionine residues

ABSTRACT: The oxidation of protein-bound methionines to form methionine sulfoxides has a broad range of biological ramifications and it is therefore important to delineate factors that influence methionine oxidation rates within a protein. Previously, neighboring residue effects and solvent accessibility (SA) had been shown to impact the susceptibility of methionine residues to oxidation. In this study, we provide proteome-wide evidence that oxidation rates of buried methionine residues are also strongly influenced by the thermodynamic folding stability of the domains where they reside. We surveyed the E. coli proteome using several proteomic methodologies and globally measured oxidation rates of methionines in the presence and absence of tertiary structure as well as folding stabilities of methionione containing domains. The data indicate that buried methionines have a wide range of protection factors (PFs) against oxidation that correlate strongly with folding stabilities. Concordantly, we show that in comparison to E. coli, the proteome of the thermophile T. thermophilus is significantly more stable and thus more resistant to methionine oxidation. These results indicate that oxidation rates of buried methionines from the native state of proteins can be used as a metric of folding stability. To demonstrate the utility of this correlation, we used native methionine oxidation rates to survey the folding stabilities of E. coli and T. thermophilus proteomes at various temperatures and suggest a model that relates the temperature dependence of the folding stabilities of these two species to their optimal growth temperatures.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Escherichia Coli Thermus Thermophilus (strain Hb8 / Atcc 27634 / Dsm 579)

SUBMITTER: Ethan Walker  

LAB HEAD: Sina Ghaemmaghami

PROVIDER: PXD030245 | Pride | 2022-04-22

REPOSITORIES: Pride