Abstract: The present disclosure provides, among other features, an enzyme electrode in which an enzyme is immobilized via more appropriate bonds. An enzyme electrode according to the present disclosure includes an electrode and a modified protein having an amino acid sequence obtained by substituting at least one lysine residue in a fusion protein between a thioredoxin reductase and a thioredoxin with a non-lysine amino acid residue, in which the modified protein is immobilized on a surface of the electrode.

Abstract: The present disclosure provides, among other features, an enzyme electrode in which an enzyme is immobilized via more appropriate bonds. An enzyme electrode according to the present disclosure includes an electrode and a modified protein having an amino acid sequence obtained by substituting at least one lysine residue in a protein that is a reductase or a dehydrogenase with a non-lysine amino acid residue, in which the modified protein is immobilized on a surface of the electrode.

Abstract: A target molecule reduction method includes: reducing a disulfide bond that is in a target molecule present in a reaction system by using thioredoxin in a reduced form, the thioredoxin being changeable between an oxidized form and the reduced form; and changing the thioredoxin from the oxidized form to the reduced form by donating, to the thioredoxin that has changed to the oxidized form due to being oxidized by the disulfide bond in the reducing, an electron to reduce the thioredoxin, the electron being from an electrode that is connected to an external power supply outside of the reaction system, wherein the thioredoxin is immobilized on a surface of the electrode directly or via a linker, and the reducing and the changing are performed with the reaction system under a basic condition.

Abstract: An immobilized enzyme electrode includes: an electrode; a redox enzyme that oxidizes or reduces a target molecule; and an electron carrier that performs electron transport between the electrode and the redox enzyme. The electron carrier is immobilized on the electrode via a first linker that is in a form of a chain, and the redox enzyme is immobilized on the electrode via a second linker that is longer than the first linker, the second linker being in a form of a chain.

Abstract: An immobilized enzyme electrode includes: an electrode; a redox enzyme that oxidizes or reduces a target molecule; and an electron carrier that performs electron transport between the electrode and the redox enzyme. The electron carrier is immobilized on the electrode via a first linker that is in a form of a chain, and the redox enzyme is immobilized on the electrode via a second linker that is longer than the first linker, the second linker being in a form of a chain.

Abstract: A fusion protein obtained by fusing a ferredoxin-thioredoxin reductase and thioredoxin via a linker peptide. The linker peptide includes glycine (G) and serine (S).

Abstract: A method for cleaving a disulfide bond in a protein includes: cleaving a disulfide bond in a protein present in a reaction system by reduction via a reduced redox protein; and reducing an oxidized redox protein produced by oxidation of the reduced redox protein in the cleaving to the reduced redox protein by donating an electron from an electrode connected to an external power supply outside the reaction system to the oxidized redox protein.

Abstract: A target molecule redox method includes: a first process of bringing a liquid containing a target molecule to a non-flowing state, and causing electron transfer between an electron carrier immobilized on an electrode connected to an external power supply outside the liquid and the target molecule to oxidize or reduce the target molecule; and a second process of bringing the liquid to a flowing state. The first process and the second process are sequentially repeated.

Abstract: An allergen inactivation method includes an inactivation step of inactivating an allergen present in a reaction system by reduction via a reduced redox protein, and a reduction process of reducing an oxidized redox protein produced by oxidation of the reduced redox protein in the inactivating to the reduced redox protein by donating an electron from an electrode connected to an external power supply outside the reaction system to the oxidized redox protein.