# US 5,710,253 A · Method for decoloring human serum albumin > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,710,253 A - Document ID: US5710253A - Status: Granted - Kind: A - Application number: 08/358,302 - Filed: 1994-12-19 - Granted: 1998-01-20 - Earliest claimed: 1993-12-17 - Assignees: The Green Cross Corporation - Inventors: Wataru Ohtani; Naoto Furuhata; Akinori Sumi; Munehiro Noda; Takao Ohmura - Web page: https://patentgrep.com/patent/US5710253A ## CPC - C07K 14/765: Serum albumin, e.g. HSA - A61P 7/00: Drugs for disorders of the blood or the extracellular fluid - 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) - A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS ## Abstract A method for decoloring a recombinant human serum albumin by treating the albumin with a reducing agent is disclosed. Also, a method for decoloring a recombinant human serum albumin by treating the albumin with a method removing free polysaccharides with a cation exchanger followed by heat treatment is disclosed. The present invention provides a recombinant human serum albumin, coloring of which is fully suppressed by preventing binding of certain coloring components, which are contained in the raw materials or contaminants secreted by a microorganism, to human serum albumin so as not to cause coloring of the human serum albumin. ## Claims ### Claim 1 A method for decoloring a recombinant human serum albumin, which comprises treating a recombinant human serum albumin (HSA), during purification thereof except in a heat treatment, with a reducing agent, thereby decoloring the recombinant HSA. ### Claim 2 (depends on 1) The method according to claim 1, wherein the reducing agent is a low molecular weight compound containing an SH group selected from the group consisting of cysteine, cysteamine, cystamine, aminopropanethiol, methionine, ethionine and glutathione, or is sulfurous acid, hyposulfurous acid, pyrosulfurour acid, phosphorous acid-sulfurous acid, phosphorous acid-pyrosulfurous acid, sulfurous acid-pyrophosphoric acid, ascorbic acid, or a salt thereof. ### Claim 3 (depends on 1) The method according to claim 1, wherein the recombinant human serum albumin concentration is from 0.01 to 25 w/v % during the treatment with the reducing agent. ### Claim 4 (depends on 1) The method according to claim 1, wherein the recombinant human serum albumin concentration is from 0.1 to 5 w/v % during the treatment with the reducing agent. ### Claim 5 (depends on 1) The method according to claim 1, wherein an amine compound known to suppress coloration of human serum albumin is present during the treatment with the reducing agent. ### Claim 6 A method for decoloring a recombinant human serum albumin (HSA), which comprises removing free polysaccharides from a recombinant human serum albumin and then heat treating said albumin in the presence of a reducing agent, thereby decoloring the recombinant HSA. ### Claim 7 (depends on 6) The method according to claim 6 wherein the treatment with the reducing agent is carried out at from 10.degree. to 100.degree. C. for 10 minutes to 240 hours. ### Claim 8 (depends on 6) The method according to claim 6, wherein the treatment with the reducing agent is carried out at from 20.degree. to 80.degree. C. for 30 minutes to 120 hours. ### Claim 9 (depends on 2) The method according to claim 2, wherein the recombinant human serum albumin to be heat treated has a free polysaccharide content of not more than 5 mg/ml when the HSA concentration is 250 mg/ml. ### Claim 10 (depends on 6) The method according to claim 6, wherein the heat treatment is carried out in the presence of a stabilizer. ### Claim 11 (depends on 6) The method according to claim 6, wherein an amine compound known to suppress coloration of human serum albumin is present during the heat treatment. ### Claim 12 A method for decoloring a recombinant human serum albumin, which comprises treating a recombinant human serum albumin (HSA) with a cation exchanger to remove free polysaccharides therefrom and then heat treating said albumin in the presence of a reducing agent, thereby decoloring the recombinant HSA. ### Claim 13 (depends on 12) The method according to claim 12, wherein the recombinant human serum albumin to be heat treated has a free polysaccharide content of not more than 5 mg/ml when the HSA concentration is 250 mg/ml. ### Claim 14 (depends on 12) The method according to claim 12, wherein the heat treatment is carried out in the presence of a stabilizer. ### Claim 15 (depends on 12) The method according to claim 12, wherein an amine compound known to suppress coloration of human serum albumin is present during the heat treatment.