Protein denaturation inhibitor and method for inhibiting protein denaturation

Abstract

To provide a method for suppressing skin irritation, skin roughness, or the like, while minimizing the impact on intended effects such as cleaning, hair dyeing, moisturization or the like against protein denaturation occurring when using a composition containing a substance having a protein denaturing action, such as a surfactant, an organic solvent or the like, or to provide an agent therefor.SOLUTION: Denaturation of the protein can be suppressed by adding 0.5 to 30% of hydrolyzed starch or hydrogenated starch hydrolysate containing 10% or more of sugars or hydrogenated sugars with a degree of polymerization of 4 or more to a composition containing the protein and a protein denaturant.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a protein denaturation inhibitor and a method for inhibiting protein denaturation. [Background technology]

[0002] Protein denaturation refers to the breakdown of a protein's structure, resulting in the loss of its original function. Various factors affect the maintenance of protein function, including temperature, pressure, pH, salt concentration, protein concentration, chaotropic salts, divalent metals, chelating agents, organic solvents, and surfactants. For example, surfactants are found in facial cleansers, body soaps, dishwashing detergents, and various cleaning agents, and are effective in reducing the interfacial tension between dirt and water, thereby removing dirt from skin and food. On the other hand, surfactants have a protein-denaturing effect, and when applied to the skin, for example, they can cause irritation and lead to skin diseases and rough skin. Therefore, less irritating surfactants are desirable. However, changes in the type and amount of surfactant can affect cleansing power, foaming, and foam quality.

[0003] Rough skin symptoms are primarily a condition in which healthy skin loses its moisture and smoothness, and it is known that skin with rough skin symptoms loses moisture more rapidly than healthy skin. Therefore, active ingredients that have been shown to improve and prevent skin diseases and rough skin have traditionally been formulated in topical skin preparations to replenish the skin's moisture-retaining function, such as polyol compounds like glycerin, amino acids, and hyaluronic acid. However, while conventional ingredients for improving and preventing rough skin excel in moisture-retaining function, the irritation-reducing effect of surfactants, i.e., the inhibitory effect on protein denaturation, has often been insufficient. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-322575 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-091627 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-161022 [Patent Document 4] Japanese Patent Application Publication No. 4-124118 [Non-patent literature]

[0005] [Non-Patent Document 1] Proceedings of the 17th Trehalose Symposium Cosmetics and Trehalose, Miyamoto Hidekazu et al., p.25-29 [Non-patent document 2] Incorporation of functional carbohydrates into body cleansers Kota Kanazawa FREGRANCE JOURNAL 2016 vol.7 p.45-50 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention aims to provide a method for suppressing skin irritation, roughness, etc., while minimizing the impact on the intended effects of a composition containing a substance having a protein-denaturing effect, such as a surfactant or organic solvent, that occurs when the composition is used, while minimizing the impact on the intended effects of the composition, such as cleansing and beauty, or to provide an agent therefor. [Means for solving the problem]

[0007] As a result of investigations aimed at solving the above problems, the inventors have found that hydrolyzed starch or hydrogenated starch hydrolysate having a specific composition is effective against protein denaturation, leading to the completion of the present invention.

[0008] That is, the present invention provides: (1) A protein denaturation inhibitor which is a hydrolyzed starch or a hydrogenated starch hydrolyzate and contains 10% or more of a sugar or hydrogenated sugar having a degree of polymerization of 4 or more; (2) The protein denaturation inhibitor according to (1), further comprising 3% or more of a sugar or hydrogenated sugar having a degree of polymerization of 5 or more. (3) A method of suppressing protein denaturation by using hydrolyzed starch or hydrogenated starch hydrolyzed with 10% or more of sugar or hydrogenated sugar with a degree of polymerization of 4 or more; (4) A method for inhibiting the denaturation of a protein by adding 0.5 to 30% of hydrolyzed starch or hydrogenated starch hydrolyzed with 10% or more of sugars or hydrogenated sugars having a degree of polymerization of 4 or more to a composition containing the protein and a protein denaturant. to provide. [Effects of the Invention]

[0009] The present invention provides a method for suppressing skin irritation, roughness, etc., while minimizing the impact of protein denaturation that occurs when using a composition containing a substance having a protein denaturing effect, such as a surfactant or organic solvent, on the intended effects of the composition, such as cleansing, hair dyeing, moisturizing, etc., or an agent therefor. Furthermore, it is believed that the protein denaturation inhibitory effect can suppress the occurrence of roughness, irritation, erythema, and inflammation of the skin that are caused by substances having a protein denaturing effect. DETAILED DESCRIPTION OF THE INVENTION

[0010] The hydrolyzed starch used in the present invention is also called starch hydrolysate, dextrin, powdered sugar, or starch syrup. It is a substance obtained by depolymerizing starch, such as amylose or amylopectin, with acids or enzymes, and is obtained as a mixture of sugars with various degrees of polymerization depending on the degree of hydrolysis. Hydrogenated starch hydrolysate is a substance having a hydrogenated structure of hydrolyzed starch. It is obtained by hydrogenating hydrolyzed starch and is also called reduced starch syrup or reduced starch syrup. It is obtained as a mixture of hydrogenated sugars with various compositions depending on the degree of polymerization and the content of the sugars contained in the hydrolyzed starch before hydrogenation. Although hydrolyzed starch and hydrogenated starch hydrolysate are used in the present invention, they may also be used in combination. From the viewpoint of the stability of coexisting substances, hydrogenated starch hydrolysate that does not have highly reactive functional groups such as formyl groups in the molecule is preferred. In addition, hydrolyzed hydrogenated starch having a branched structure derived from amylopectin, i.e., α-1,6 bonds, is known to suppress the growth of microorganisms, and is expected to contribute to the stability of compositions to which the agent of the present invention is applied.

[0011] The content of sugars or hydrogenated sugars (hereinafter sometimes referred to as "sugars") with different degrees of polymerization in each of the starch hydrolysates or hydrogenated starch hydrolysates is expressed as the percentage of the mass of each sugar relative to the total mass of the sugars (hereinafter sometimes referred to as "sugar composition"). The sugar composition can be confirmed by high-performance liquid chromatography (HPLC). HPLC is performed using an aqueous solution of the sugars as a sample to obtain a chromatogram. The total sum of the peak areas in the obtained chromatogram corresponds to the total mass of the sugars, and each peak area corresponds to the mass of each sugar, allowing the mass proportion of each sugar or hydrogenated sugar to be determined. HPLC conditions may be set as appropriate.

[0012] Hydrolyzed starch or hydrogenated starch hydrolysates containing 10%, preferably 20%, more preferably 60%, and even more preferably 70% of components with a degree of polymerization of 4 or higher, and 4%, preferably 15%, more preferably 55%, and even more preferably 65% ​​of components with a degree of polymerization of 5 or higher, can be used as is as a protein denaturation inhibitor of the present invention. The hydrolyzed starch used in the present invention can be produced by controlling the hydrolysis of starch to obtain the sugar composition described above, and may be further converted into hydrogenated starch hydrolysates using a hydrogenation reaction. Hydrolyzed starches or hydrogenated starch hydrolysates with different compositions may also be mixed. There are no limitations on the methods used for starch hydrolysis and hydrogenation.

[0013] The protein denaturation inhibitor of the present invention exhibits the effect of inhibiting not only protein denaturation caused by surfactants, but also protein denaturation caused by factors such as temperature, pressure, pH, organic solvents, and chaotropic salts. When using the protein denaturation inhibitor of the present invention, it can be used in coexistence with the protein by mixing, contact, penetration, etc., but when using a substance that causes protein denaturation, it may be mixed with the protein to form a composition and then mixed with the protein. For example, when using a surfactant, the protein denaturation inhibitor of the present invention can be incorporated into an external skin preparation, which can be allowed to penetrate into the skin before use, and then a composition containing a surfactant such as a cleanser (hereinafter sometimes referred to as a "surfactant-containing composition") can be used to achieve the effects of the present invention. However, the protein denaturation inhibitor of the present invention can also be incorporated into a surfactant-containing composition and used to achieve the effects of the present invention.

[0014] Compositions containing substances with protein-denaturing properties (hereinafter also referred to as the target compositions of the present invention) are not particularly limited, but examples include cleansing agents such as facial cleansers, body soaps, and hand soaps, hair dyes, ointments, creams, lotions, packs, bath additives, dishwashing detergents, laundry detergents, general-purpose detergents, and topical skin preparations.

[0015] The amount of the protein denaturation inhibitor of the present invention to be contained in the target composition of the present invention varies depending on the type of target composition of the present invention and the amount of the substance having a protein denaturing effect, but for example, in a composition containing a surfactant, it is contained in an amount of 0.5 to 30%, preferably 0.8 to 10%, in terms of solid content. There are no particular restrictions on the method for incorporating the protein denaturation inhibitor into the target composition of the present invention, and the solid or solution may be dissolved and mixed by any method.

[0016] Surfactants, which are a type of substance that has a protein denaturing effect, include various anionic surfactants, mixtures of various fatty acids and their salts, α-acylsulfonates, alkylsulfonates, alkylarylsulfonates, amphoteric surfactants, nonionic surfactants, cationic surfactants, etc. Surfactants may be used alone or in combination.

[0017] The subject composition of the present invention can contain any substance as long as it does not impair the protein denaturation inhibitory effect. For example, base materials include oils and fats, silicones, sterols, water-soluble polymers, chelating agents, neutralizing agents, pH adjusters, antioxidants, and ingredients used in cosmetics and pharmaceutical skin preparations, such as moisturizers, vitamins, whitening agents, astringents, cooling agents, and various extracts. As mentioned above, the protein denaturation inhibitor of the present invention also exhibits inhibitory effects against substances that have a protein denaturing effect, such as chaotropic salts and organic solvents, making it possible to incorporate these ingredients in larger amounts than conventional compositions. Examples of chaotropic salts include urea, and examples of organic solvents include ethanol, ethyl acetate, butyl acetate, and propylene glycol.

[0018] The inhibitory effect on protein denaturation can be determined by quantifying the amount of undenatured protein before and after the action of a protein-denaturing substance, using known methods, such as comparing the peak heights of chromatograms obtained by gel permeation chromatography (size exclusion chromatography). [Example]

[0019] Examples of the present invention will be described below, but the present invention is not limited to these examples in any way.

[0020] In the examples and comparative examples, sugars and hydrogenated sugars having the sugar compositions shown in Table 1 were used.

[0021] [Table 1]

[0022] The degree of protein denaturation by surfactants was measured according to the method of Miyazawa et al. (Journal of the Society of Cosmetic Engineers of Japan, 18(2), 96-105(1984)). (Preparation of protein solution)

[0023] Egg white albumin (Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in 0.05 M phosphate buffer (pH 7) containing 0.15 M Na2SO4 to prepare 0.025% and 0.1% (w / v) egg white albumin buffer solutions (hereinafter referred to as "protein solutions"). (Preparation of sample solution)

[0024] The protein solution, surfactant aqueous solution (0.075% sodium lauryl sulfate aqueous solution (hereinafter referred to as "SDS aqueous solution")), and carbohydrate solution were mixed in the proportions (parts by volume) shown in Table 2, and the mixture was allowed to react in a constant temperature bath at 25°C for 24 hours (hereinafter referred to as "sample solution") immediately after mixing.

[0025] [Table 2] (Measurement of protein denaturation)

[0026] Protein denaturation was measured by HPLC (High Performance Liquid Chromatography). HPLC analysis was performed using a Hitachi (High Performance Liquid Chromatograph Primaide®) HPLC analyzer and a TOSHO / TSK G3000SW column. The mobile phase was 0.05 M phosphate buffer (pH 7) containing 0.15 M NaSO. Analysis was performed under the following conditions: flow rate 1.0 mL / min, detection wavelength 220 nm, injection volume 25 μL, and column temperature room temperature. (Measurement of control solution)

[0027] A solution (hereinafter referred to as the "control sample solution") was prepared by mixing 80 parts by volume of a 0.025% protein solution, 10 parts by volume of an SDS aqueous solution, and 10 parts by volume of water, and the mixture was allowed to react in a constant temperature bath at 25°C for 24 hours starting immediately after mixing. A solution (hereinafter referred to as the "control standard solution") was also prepared by mixing 80 parts by volume of a 0.025% protein solution and 10 parts by volume of water, and the standard denaturation rate was calculated using the following formula. Control degeneration rate (RDR) = ((HR0 - HRs) / HR0) HR0: Peak height of the chromatogram derived from the native protein of the reference solution HRs: Peak heights of the chromatogram derived from the undenatured protein in the control sample solution (Measurement of sample solution)

[0028] Each sample solution and an unreacted solution (hereinafter referred to as "reference solution") in which the SDS aqueous solution in each sample solution was replaced with water were analyzed by HPLC, and the sample modification rate was calculated using the following formula. Sample denaturation rate (DR) = ((H0-Hs) / H0) H0: Peak height of the chromatogram derived from the native protein of the reference solution Hs: chromatogram peak height derived from undenatured proteins in the sample solution (Evaluation of protein denaturation inhibitory effect)

[0029] The value calculated using the following formula was used as the protein denaturation index. A smaller value for the protein denaturation index indicates a higher inhibitory effect on protein denaturation. The results are shown in Table 3. Protein denaturation index = (DR / RDR)

[0030] [Table 3]

[0031] In the examples, it was revealed that the presence of hydrogenated starch hydrolysate reduces protein denaturation of surfactants. [Industrial Applicability]

[0032] According to the present invention, it is possible to suppress protein denaturation caused by substances that have a protein denaturing effect.

Claims

1. A protein denaturation inhibitor which is a hydrolyzed starch or a hydrogenated starch hydrolyzed by polymerization and contains 10% or more of a sugar or hydrogenated sugar having a degree of polymerization of 4 or more.

2. 2. A protein denaturation inhibitor according to claim 1, further comprising 3% or more of sugars or hydrogenated sugars with a degree of polymerization of 5 or more.

3. A method for suppressing protein denaturation using hydrolyzed starch or hydrogenated starch hydrolyzed with 10% or more of sugars or hydrogenated sugars having a degree of polymerization of 4 or more.

4. A method for inhibiting the denaturation of a protein by adding 0.5 to 30% of hydrolyzed starch or hydrogenated starch hydrolysate, which contains 10% or more of sugars or hydrogenated sugars with a degree of polymerization of 4 or more, to a composition containing the protein and a protein denaturant.

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