IP Library Granted Patent US 12687545
Granted Patent B2
US 12687545 · App. 18/029,086 · Granted Jul 21, 2026

Fluorescent protein sensor capable of quantitatively measuring oxidation degree of methionine residues of specific protein, and use thereof

Inventors: Byung Cheon Lee (Seoul, KR); Hae Min Lee (Seoul, KR)
Assignee: GERONMED, CO. LTD
G01N33/6815C07K14/315C07K14/35C07K2319/60G01N2800/7009
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Quick Facts
Patent No.
US 12687545
App. No.
18/029,086
Granted
Jul 21, 2026
Kind
B2
Abstract

A fluorescent protein sensor capable of quantitatively measuring oxidation degree of methionine residues of a specific protein, and a use thereof. Specifically, a fluorescent biosensor recombinant protein in which an MsrB protein, a cpYFP protein, a thioredoxin 3 protein, a linker protein and a G protein are linked in this order, and which is capable of quantitatively measuring the oxidation degree of methionine residues of a target protein; a fluorescent biosensor comprising same; a method for measuring oxidation degree of methionine residues of a target protein; and an information providing method for diagnosis of oxidative stress-associated diseases; and a method for screening for a therapeutic agent for oxidative stress-associated diseases. A recombinant protein for a fluorescent biosensor for accurately and quantitatively measuring, through the detection of a specific change in fluorescence, oxidation degree of methionine residues of a specific protein, but not all proteins, even in a mixed biological sample.

Claims (238)

1 . A recombinant protein for a fluorescent bio-sensor configured to measure a degree of oxidation of methionine residues in a target protein, the recombinant protein comprising:

methionine sulfoxide reductases B (MsrB) protein; circularly permuted yellow fluorescence protein (cpYFP); thioredoxin 3 protein; linker protein; and protein G, which are sequentially linked, wherein the linker protein consists of 489 th to 521 st amino acids of an amino acid sequence of SEQ ID NO: 2.

2 . The recombinant protein of claim 1 , wherein the recombinant protein consists of the amino acid sequence of SEQ ID NO: 2.

3 . A polynucleotide encoding the recombinant protein of claim 1 .

4 . The polynucleotide of claim 3 , wherein the polynucleotide consists of the nucleotide sequence of SEQ ID NO: 1.

5 . An expression vector comprising the polynucleotide of claim 3 .

6 . A transformant transformed with the expression vector of claim 5 .

7 . A fluorescent bio-sensor for measuring a degree of oxidation of methionine residues of a target protein, comprising the recombinant protein of claim 1 .

8 . A quantitative detection composition for measuring a degree of oxidation of methionine residues in a target protein, the quantitative detection composition comprising: the recombinant protein of claim 1 , and a primary antibody for a target protein to be detected.

9 . A method of measuring a degree of oxidation of methionine residues in a target protein, comprising:

(1) preparing a sample comprising a target protein comprising methionine residues;

(2) treating the sample with a primary antibody against the target protein to bind the primary antibody to the target protein;

(3) treating the recombinant protein for a fluorescent bio-sensor of claim 1 ; and

(4) measuring a fluorescence spectrum value of the recombinant protein for a fluorescent bio-sensor.

10 . The method of claim 9 , wherein the measurement of the fluorescence spectrum value is calculated using the following Equation.

50

0

nm

value

of

the

excitation

spectrum

(

fixed

at

535

nm

emission

wavelength

)

415

nm

value

of

the

excitation

spectrum

(

fixed

at

535

nm

emission

wavelength

)

=

F

500

n

m

/

F

415

n

m

Equation

11 . The method of claim 10 , wherein the greater the oxidation of methionine residues in the target protein, the lower a numerical value of the fluorescence spectrum value is.

12 . A method of providing information for diagnosis of oxidative stress-related diseases, the method comprising treating a biological sample isolated from a test subject with the composition of claim 8 , and then comparing a fluorescence spectrum value of a recombinant protein for a fluorescence bio-sensor with a fluorescence spectrum value of a normal control group, wherein the fluorescence spectrum value is calculated by the following Equation.

50

0

nm

value

of

the

excitation

spectrum

(

fixed

at

535

nm

emission

wavelength

)

415

nm

value

of

the

excitation

spectrum

(

fixed

at

535

nm

emission

wavelength

)

=

F

500

n

m

/

F

415

n

m

Equation

13 . The method of claim 12 , wherein the sample is a cell, tissue, blood, plasma, serum, saliva, or urine.

14 . The method of claim 12 , wherein the oxidative stress-related diseases are selected from the group consisting of cancer, stroke, myocardial infarction, angina, arteriosclerosis, infertility, hepatitis, osteoarthritis, cataracts, lipid metabolic disease, heart failure, hypertensive heart disease, arrhythmia, and aging.

15 . A method of screening for a therapeutic agent for an oxidative stress-related disease, the method comprising:

(1) inducing oxidative stress in a sample comprising a protein containing methionine residues;

(2) treating the sample with a candidate drug; and

(3) treating the candidate substance-treated sample with the composition of claim 8 , and comparing a fluorescence spectrum value of a recombinant protein for a fluorescent bio-sensor with a fluorescence spectrum value of a control group not treated with the candidate drug, wherein the fluorescence spectrum value is calculated by the following Equation.

50

0

nm

value

of

the

excitation

spectrum

(

fixed

at

535

nm

emission

wavelength

)

415

nm

value

of

the

excitation

spectrum

(

fixed

at

535

nm

emission

wavelength

)

=

F

500

n

m

/

F

415

n

m

Equation

16 . The method of claim 15 , further comprising determining the candidate drug as a therapeutic agent for an oxidative stress-related disease, when the fluorescence spectrum value of treatment with the candidate drug is greater than the fluorescence spectrum value of the control group.

17 . The method of claim 15 , wherein the oxidative stress-related disease is selected from the group consisting of cancer, stroke, myocardial infarction, angina pectoris, arteriosclerosis, infertility, hepatitis, osteoarthritis, cataracts, lipid metabolic syndrome, heart failure, hypertensive heart disease, arrhythmia, and aging.