# US 12,215,140 B2 · Method of stabilizing protein contained in specimen and solution for stabilizing protein contained in specimen > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,215,140 B2 - Document ID: US12215140B2 - Status: Granted - Kind: B2 - Application number: 16/977,338 - Filed: 2019-02-28 - Published: 2020-12-31 - Granted: 2025-02-04 - Earliest claimed: 2018-03-02 - Assignees: Eiken Kagaku Kabushiki Kaisha - Applicants: Eiken Kagaku Kabushiki Kaisha - Inventors: Nozomi Sakamaki; Hidenori Taguchi; Mitsuru Makinodan; Miyu Yamada - Web page: https://patentgrep.com/patent/US12215140B2 ## CPC - C07K 14/805: Haemoglobins; Myoglobins - G01N 33/5306: {Improving reaction conditions, e.g. reduction of non-specific binding, promotion of specific binding} - G01N 33/72: involving blood pigments, e.g. haemoglobin, bilirubin {or other porphyrins; involving occult blood} - G01N 33/721: {Haemoglobin} - C07K 14/46: from vertebrates - C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract The present invention provides a method of stabilizing a protein. The method includes a step of causing a protein contained in a specimen derived from a living body to coexist with an arylboronic acid. The protein contained in the specimen derived from the living body is at least one type selected from the group consisting of hemoglobin, haptoglobin, and a hemoglobin-haptoglobin complex. According to the present invention, it is possible to stabilize a protein such as a blood protein contained in the specimen derived from a living body. The present invention further provides a stabilizing solution for stabilizing a protein contained in a specimen derived from a living body and a method and a kit for detecting a protein contained in a specimen derived from a living body. ## Claims ### Claim 1 A method of stabilizing a protein contained in a specimen derived from a living body, the method comprising a step of causing the protein contained in the specimen derived from the living body to coexist with an arylboronic acid and a sugar in a solution, wherein the protein contained in the specimen derived from the living body is at least one selected from the group consisting of hemoglobin, haptoglobin, and a hemoglobin-haptoglobin complex. ### Claim 2 (depends on 1) The method according to claim 1, wherein the arylboronic acid is at least one selected from the group consisting of phenylboronic acid and derivatives thereof. ### Claim 3 (depends on 1) The method according to claim 1, wherein the arylboronic acid is at least one selected from the group consisting of phenylboronic acid, hydroxyphenylboronic acid, carboxyphenylboronic acid, aminophenylboronic acid, and salts thereof. ### Claim 4 (depends on 1) The method according to claim 1, wherein the causing the protein contained in the specimen derived from the living body to coexist with an arylboronic acid comprises dispersing the protein contained in the specimen derived from the living body in a solution containing the arylboronic acid, and a concentration of the arylboronic acid in the solution is 0.1 mmol/L or more. ### Claim 5 (depends on 1) The method according to claim 1, wherein the sugar is at least one selected from the group consisting of sugar alcohol, monosaccharide, and disaccharide. ### Claim 6 (depends on 1) The method according to claim 1, wherein the sugar is at least one selected from the group consisting of sorbitol, glucose, mannitol, fructose, xylitol, erythritol, sucrose, trehalose, lactose, and maltose. ### Claim 7 (depends on 1) The method according to claim 1, wherein the causing the protein contained in the specimen derived from the living body to coexist with the arylboronic acid and a sugar comprises dispersing the protein contained in the specimen derived from the living body in the solution containing the arylboronic acid and the sugar, and a concentration of the sugar in the solution is 5 mmol/L or more. ### Claim 8 (depends on 1) The method according to claim 1, wherein the specimen derived from the living body contains at least hemoglobin, and the method further comprises bringing the hemoglobin and haptoglobin into contact with each other to form a complex of hemoglobin and haptoglobin. ### Claim 9 (depends on 1) The method according to claim 1, wherein the specimen derived from the living body is feces, saliva, or urine. ### Claim 10 A stabilizing solution for stabilizing a protein contained in a specimen derived from a living body, wherein the stabilizing solution comprises an arylboronic acid, a sugar, and the protein contained in the specimen derived from the living body is at least one selected from the group consisting of hemoglobin, haptoglobin, and a hemoglobin-haptoglobin complex. ### Claim 11 (depends on 10) The stabilizing solution according to claim 10, wherein the arylboronic acid is at least one selected from the group consisting of phenylboronic acid and derivatives thereof. ### Claim 12 (depends on 10) The stabilizing solution according to claim 10, wherein the arylboronic acid is at least one selected from the group consisting of phenylboronic acid, hydroxyphenylboronic acid, carboxyphenylboronic acid, aminophenylboronic acid, and salts thereof. ### Claim 13 (depends on 10) The stabilizing solution according to claim 10, wherein the sugar is at least one selected from the group consisting of sorbitol, glucose, mannitol, fructose, xylitol, erythritol, sucrose, trehalose, lactose, and maltose. ### Claim 14 (depends on 10) The stabilizing solution according to claim 10, comprising haptoglobin. ### Claim 15 (depends on 10) The stabilizing solution according to claim 10, wherein the specimen is feces, saliva, or urine. ### Claim 16 (depends on 10) The stabilizing solution according to claim 10, wherein the stabilizing solution is a solution for preserving the specimen derived from the living body. ### Claim 17 (depends on 11) A method of detecting a protein in a specimen derived from a living body, the method comprising: adding the specimen derived from the living body to the stabilizing solution according to claim 11 to obtain a sample containing the specimen; and detecting the protein in the sample by an immunological measurement method, wherein the protein in the specimen derived from the living body is at least one selected from the group consisting of hemoglobin, haptoglobin, and a hemoglobin-haptoglobin complex. ### Claim 18 (depends on 17) The method according to claim 17, wherein the specimen derived from the living body contains at least hemoglobin, and the hemoglobin in the sample forms a complex together with haptoglobin. ### Claim 19 (depends on 18) The method according to claim 18, wherein the stabilizing solution further comprises haptoglobin.