Reduction of oxidated methionine peptides for mass spectrometry
AssigneeCalifornia Institute of Technology
InventorsMichael Sweredoski, Annie Moradian, Tanya R. Yakushi, Sonja Hess, Roxana Eggleston-Rangel
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Abstract
A method for preparing a methionine containing peptide or protein for analysis by mass spectrometry by incubating the methionine containing peptide or protein with a heterologous methionine sulfoxide reductase A (MsrA), a heterologous methionine sulfoxide reductase B (MsrB), or a heterologous methionine sulfoxide reductase AB (MsrAB) enzyme results in the reduction of an oxidized methionine containing peptide or protein.
Claims20
A method for reducing a methionine containing peptide or protein for mass spectrometry analysis, comprising:
- obtaining a heterologous methionine sulfoxide reductase (Msr) enzyme composition comprising a heterologous Msr protein expressed and isolated from a host cell, the heterologous Msr enzyme composition comprising:
- a heterologous MsrA protein and a heterologous MsrB protein,
- a heterologous MsrAB protein from Neisseria, or
- a combination thereof;
- immobilizing the heterologous Msr enzyme composition on a surface to form an immobilized heterologous Msr enzyme composition,
- incubating the methionine containing peptide or protein with the immobilized heterologous Msr enzyme composition;
- and
- separating the methionine containing peptide or protein from the immobilized heterologous Msr enzyme composition after the incubating.
A method for preparing a methionine containing peptide or protein for mass spectrometry analysis, comprising:
- obtaining a heterologous methionine sulfoxide reductase (Msr) enzyme composition comprising a heterologous Msr protein expressed and isolated from a bacterial, yeast, or human host cell, the heterologous Msr enzyme composition comprising:
- a heterologous MsrA protein and a heterologous MsrB protein,
- a heterologous MsrAB protein from Neisseria, or
- a combination thereof;
- immobilizing the heterologous Msr enzyme composition on a resin bead or a membrane filter to form an immobilized heterologous Msr enzyme composition;
- activating the immobilized heterologous Msr enzyme composition to form an activated heterologous Msr enzyme composition;
- adding the methionine containing peptide or protein to the activated heterologous Msr enzyme composition;
- and
- separating the methionine containing peptide or protein from the activated heterologous Msr enzyme composition.
Dependencies are inferred from the claim text.