Screening method for odor-controlling materials

Abstract

To provide a method for efficiently screening a candidate substance for an odor-suppressing material from among test substances by using an olfactory receptor that is responsive to an odor-causing substance.SOLUTION: Provided is a method for screening an odor-suppressing material. The method comprises: adding a test substance and an odor-causing substance to an olfactory receptor polypeptide selected from the group consisting of OR2L3 and a polypeptide containing an amino acid sequence having at least 80% identity with the amino acid sequence of OR2L3 and responsive to the odor-causing substance; measuring the response of the olfactory receptor polypeptide to the odor-causing substance; and identifying that the test substance that suppresses the response of the olfactory receptor polypeptide based on the measured response is a candidate substance for the odor-suppressing material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for screening malodor control materials. [Background technology]

[0002] In recent years, as consumer preferences and living environments have become more diverse, an increasing number of people are becoming sensitive to odors and unpleasant smells around them. These odors range from odors in the living space to slight unpleasant odors (off-flavors) in food, and technology that can more effectively reduce and eliminate unpleasant odors is needed to improve quality of life.

[0003] Typical substances that cause unpleasant odors in living spaces include skatole and indole, which are contained in body odor, fecal odor, putrid odor, etc. (Patent Document 1). These malodorous substances are tryptophan metabolites derived from animal proteins and are produced by in vivo and microbial metabolism. As a result, they are found not only in human body odor and excrement, but also in animal-derived foods such as dairy products, where they contribute to the degradation of food palatability as off-flavors (Non-Patent Document 1).

[0004] Many substances are known to cause off-flavors in food, including, for example, α-terpineol, 4-terpineol, and p-methylacetophenone, which are deterioration odors derived from citrus fruits and the like (Non-Patent Document 2).

[0005] In the conventional method of searching for substances that reduce or eliminate unpleasant odors, a huge number of candidate substances have to be checked one by one by an odor evaluation specialist, resulting in low throughput. On the other hand, a molecular biological method that has been established in recent years searches for olfactory receptors that respond to substances that cause malodors, and by using these olfactory receptors, it is possible to quickly screen candidate substances for malodor suppression materials.

[0006] There are approximately 400 types of olfactory receptors in humans, and a single odorant responds to many of them. However, some of the responsive receptors are called broadly tuned olfactory receptors, which recognize a wide range of odorants without discrimination. Therefore, it is important to know which of the several receptors to which odor-causing substances respond is highly relevant to unpleasant sensations. For example, Non-Patent Document 3 reports that the olfactory receptor OR7D4 is a truly important receptor related to the unpleasant odor of androstenone. Non-Patent Document 4 lists many broadly tuned olfactory receptors, such as OR2W1, that respond broadly to a wide range of odors regardless of their scent tone.

[0007] Patent Document 2 discloses OR2W1, OR5P3, OR5K1, and OR8H1 as olfactory receptors that respond to skatole or indole, which are substances that cause malodors, and describes that the odor of skatole or indole can be suppressed by inhibiting the response of these olfactory receptors. Furthermore, Patent Document 3 discloses that o-isopropylphenol, an odorous substance brought by passengers onto transportation vehicles such as vehicles, responds to the olfactory receptor OR2L3. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-036434 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-250958 [Patent Document 3] Japanese Patent Application Publication No. 2017-176134 [Patent Document 4] Japanese Patent Application Laid-Open No. 2008-136841 [Non-patent literature]

[0009] [Non-Patent Document 1] J. Agric. Food Chem. 2001, 49, 10, 4825-4832 [Non-patent document 2] Nippon Nogeikagaku Kaishi Vol. 55, No. 1, pp. 23-30, 1981 [Non-patent document 3] Nature. 2007 Sep 27;449(7161):468-72. [Non-patent document 4] Flavor Fragr. J. 2015, 30, 342-361 [Non-patent document 5] Nature Communications 10:209 (2019) Summary of the Invention [Problem to be solved by the invention]

[0010] Many of the olfactory receptors that have been disclosed to respond to skatole and indole are broadly tuned olfactory receptors, and it was unclear and unknown which olfactory receptor characterizes malodor recognition. Furthermore, no olfactory receptors that clearly respond to α-terpineol, 4-terpineol, and p-methylacetophenone have been known to date. Under these circumstances, it is desirable to search for olfactory receptors that respond to malodor-causing substances such as skatole, indole, α-terpineol, 4-terpineol, and p-methylacetophenone, and to provide a method for efficiently screening candidate substances for malodor-suppressing materials, as well as a malodor-suppressing composition that reduces the unpleasantness of such malodors. [Means for solving the problem]

[0011] As a result of extensive research aimed at solving the above-mentioned problems, the present inventors have newly discovered that certain malodorous substances, such as skatole, indole, α-terpineol, 4-terpineol, and p-methylacetophenone, characteristically respond to the olfactory receptor OR2L3. By aggregating the OR2L3 response results for hundreds of odorants, it was discovered that a certain number of malodorous substances are among the substances that respond to OR2L3. This new finding led to the identification of OR2L3 as an important olfactory receptor for recognizing malodors. Further research by the present inventors has revealed that OR2L3 can be used to evaluate and select malodor-suppressing materials by utilizing the masking effect of olfactory receptor antagonists.

[0012] That is, the present invention provides a method for screening candidate substances for inhibiting OR2L3-responsive malodors, such as skatole, indole, α-terpineol, 4-terpineol, or p-methylacetophenone, as shown below.

[0013] [1] 1. A method for screening malodor control materials, comprising the steps of: adding a test substance and a malodor-causing substance to an olfactory receptor polypeptide selected from the group consisting of OR2L3 and polypeptides that contain an amino acid sequence that is at least 80% identical to the amino acid sequence of OR2L3 and that are responsive to the malodor-causing substance; measuring the response of said olfactory receptor polypeptide to a malodor-causing substance; and identifying a test substance that inhibits the response of the olfactory receptor polypeptide based on the measured response, i.e., identifying a test substance that inhibits the response of the olfactory receptor polypeptide based on the measured response as a candidate malodor-controlling material. A method comprising: [2] The method according to [1], wherein the malodor is skatole odor, indole odor, α-terpineol odor, 4-terpineol odor, or p-methylacetophenone odor. [3] The method according to [1], wherein the malodor is fecal odor, bad breath, deteriorated odor of dairy products, or deteriorated odor of citrus fruits. [4] The method according to [1], wherein the malodor is an odor caused by a compound, composition or mixture that is unpleasant to humans. [5] The method according to any one of [1] to [4], wherein the response of the olfactory receptor polypeptide to a malodor-causing substance is measured on cells isolated from a living organism expressing the olfactory receptor, or on cells in which the olfactory receptor has been artificially expressed by genetic manipulation. [6] The method according to any one of [1] to [5], wherein the response of an olfactory receptor is measured by a reporter gene assay or calcium imaging. [Effects of the Invention]

[0014] The method of the present invention allows screening for candidate malodor-suppressing materials that can inhibit the binding of malodor-causing substances to the olfactory receptor OR2L3. Furthermore, even if the target malodor is a mixture of unidentified causative substances, it is easy to predict the possibility that the test substance will respond to OR2L3. Therefore, simply confirming the OR2L3 response makes it possible to apply the screening method for malodor-suppressing materials, which is also useful for selecting selective deodorizing substances for unidentified malodorous substances. It is predicted that similar effects will be obtained when a polypeptide containing an amino acid sequence at least 80% identical to the amino acid sequence of OR2L3 and exhibiting responsiveness to malodor-causing substances is used as the olfactory receptor. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 shows the results of measuring the response of the olfactory receptor OR2L3 to skatole. [Figure 2] FIG. 1 shows the results of measuring the response of the olfactory receptor OR2L3 to indole. [Figure 3] FIG. 1 shows the results of measuring the response of the olfactory receptor OR2L3 to α-terpineol. [Figure 4] FIG. 1 shows the results of measuring the response of the olfactory receptor OR2L3 to 4-terpineol. [Figure 5] FIG. 1 shows the results of measuring the response of the olfactory receptor OR2L3 to p-methylacetophenone. [Figure 6] FIG. 1 shows the response-suppressing effect of the olfactory receptor OR2L3 to skatole due to the addition of cis-3-hexenyl hexanoate. [Figure 7] FIG. 1 shows the effect of adding Guavacoa (registered trademark) on suppressing the response of the olfactory receptor OR2L3 to skatole. [Figure 8] FIG. 1 shows the effect of adding Dextranbar (registered trademark) on the suppression of the response of the olfactory receptor OR2L3 to skatole. [Figure 9] FIG. 1 shows the effect of adding Hingenol (registered trademark) on the suppression of the response of the olfactory receptor OR2L3 to skatole. [Figure 10] FIG. 1 shows the effect of adding Guavacoa (registered trademark) on suppressing the response of the olfactory receptor OR2L3 to indole. [Figure 11] FIG. 1 shows the effect of adding Dextranbar (registered trademark) on the suppression of the response of the olfactory receptor OR2L3 to indole. [Figure 12] FIG. 1 shows the effect of adding Hingenol (registered trademark) on suppressing the response of the olfactory receptor OR2L3 to indole. DETAILED DESCRIPTION OF THE INVENTION

[0016] The screening method of the present invention will now be described in detail. As described above, the screening method of the present invention comprises the following steps: adding a test substance and a malodor-causing substance to an olfactory receptor polypeptide selected from the group consisting of OR2L3 and polypeptides that contain an amino acid sequence that is at least 80% identical to the amino acid sequence of OR2L3 and that are responsive to the malodor-causing substance; Measuring the response of the olfactory receptor polypeptide to a malodor-causing substance; and identifying a test substance that inhibits the response of the olfactory receptor polypeptide based on the measured response as a candidate malodor-controlling material; The present invention can be carried out, for example, according to the following embodiments.

[0017] In one embodiment, the present invention provides a method for screening candidate substances for malodor-suppressing materials from test substances using the olfactory receptor OR2L3, which is responsive to malodor-causing substances, comprising: (i) contacting a malodor-causing substance with an olfactory receptor (olfactory receptor polypeptide) selected from the group consisting of OR2L3 and proteins (polypeptides) that contain an amino acid sequence that is 80% or more identical to the amino acid sequence of OR2L3 and that is responsive to a malodor-causing substance, and measuring the response of the olfactory receptor to the malodor-causing substance; (ii) measuring the response of the olfactory receptor used in step (i) in the absence of a malodor-causing substance; (iii) comparing the measurement results in steps (i) and (ii) to calculate a change in responsiveness; (iv) mixing a test substance with the malodor-causing substance in step (i) and calculating the change in response in the same manner as in step (iii); (v) selecting the test substance for which the value in step (iv) is reduced compared to step (iii) as a candidate substance for the malodor-controlling material; The present invention is characterized in that it includes:

[0018] The screening method of the present invention selects candidate odor-suppressing materials from among test substances using the responsiveness of the test substance to an olfactory receptor selected from the group consisting of olfactory receptor OR2L3 and proteins (polypeptides) that contain an amino acid sequence that is 80% or more identical to the amino acid sequence of OR2L3 and that is responsive to odor-causing substances as an indicator.

[0019] It is generally known that a single odorant activates multiple olfactory receptors, resulting in emotions and behaviors such as likes and dislikes, attraction and avoidance. According to Non-Patent Document 5, each olfactory receptor is responsible for determining the "quality" of an odor. After measuring the OR2L3 response to hundreds of odorants and diligently examining and consolidating the data, it was found that a certain number of substances responding to OR2L3 are malodorous, and OR2L3 is therefore associated with the recognition of malodors equivalent to dislike or avoidance. Therefore, by evaluating the responsiveness of a test substance to the olfactory receptor OR2L3, it is possible to select candidate substances from the test substances that can prevent malodor-causing substances from binding to the olfactory receptor. In this specification, the term "test substance" refers to, but is not limited to, the subject of investigation of the malodor-suppressing effect, and may refer to a compound, composition, or mixture. Furthermore, in this specification, the term "malodor-suppressing material" refers to, but is not limited to, a compound, composition, or mixture that can suppress malodor. Each step of the screening method of the present invention will be explained below.

[0020] <Process (i)> In step (i), an olfactory receptor selected from the group consisting of OR2L3 and proteins (polypeptides) that contain an amino acid sequence that is 80% or more identical to the amino acid sequence of OR2L3 and that is responsive to the malodor-causing substance is contacted with the malodor-causing substance, and the response of the olfactory receptor to the malodor-causing substance is measured.

[0021] The olfactory receptor used is an olfactory receptor selected from the group consisting of OR2L3 and proteins (polypeptides) that contain an amino acid sequence that is 80% or more identical to the amino acid sequence of OR2L3 and that is responsive to odor-causing substances. OR2L3 is registered in GenBank as NM_001004687, and is a protein (polypeptide) consisting of the amino acid sequence (SEQ ID NO: 2) encoded by DNA having the nucleotide sequence shown in SEQ ID NO: 1. The olfactory receptor OR2L3 selectively responds to certain malodorous substances, such as skatole, and therefore screening methods using OR2L3 are expected to contribute to the development of malodor-suppressing materials.

[0022] The olfactory receptor may be selected from the group consisting of proteins (polypeptides) that contain an amino acid sequence that is 80% or more, preferably 85% or more, more preferably 90% or more, even more preferably 95% or more, and particularly preferably 98% or more identical to the amino acid sequence of OR2L3 and that is responsive to malodor-causing substances. In this specification, the sequence identity of the amino acid sequence is calculated using the BLAST search algorithm (publicly available from NCBI). The olfactory receptor may be used alone or in combination of two or more.

[0023] In the present invention, the term "malodor-causing substances" refers to OR2L3-responsive compounds, compositions, or mixtures that cause discomfort to humans, such as fecal odor, bad breath, deteriorated odors from dairy products, or deteriorated odors from citrus fruits, and are typified by skatole, indole, α-terpineol, 4-terpineol, or p-methylacetophenone.

[0024] In the present invention, the method of contacting an olfactory receptor with a malodor-causing substance and measuring the olfactory receptor response to the malodor-causing substance is not particularly limited. For example, the olfactory receptor response may be measured by contacting the malodor-causing substance with cells isolated from an organism expressing the olfactory receptor, or by contacting the malodor-causing substance with cells in which the olfactory receptor has been artificially expressed by genetic manipulation. The contact time between the olfactory receptor and the malodor-causing substance is not universally specified because it depends on the concentration of the malodor-causing substance and the measurement method, but the response may be measured immediately after contact. Typically, the contact time is 0 to 4 hours, preferably 2 to 4 hours, in reporter gene assays, and several seconds to several minutes in calcium imaging.

[0025] Cells in which olfactory receptors are artificially expressed through genetic manipulation can be produced by transforming cells with a vector incorporating a gene encoding the olfactory receptor.

[0026] In a preferred embodiment of the present invention, the N-terminal 20 amino acid residues of bovine rhodopsin may be incorporated together with the olfactory receptor. By incorporating the N-terminal 20 amino acid residues of bovine rhodopsin, the expression of the olfactory receptor on the cell membrane can be promoted. Bovine rhodopsin is registered in GenBank as NM_001014890. Bovine rhodopsin is a protein (polypeptide) consisting of an amino acid sequence (SEQ ID NO: 4) encoded by the DNA from the 1st to 1047th positions of the base sequence shown in SEQ ID NO: 3. In addition, instead of bovine rhodopsin, a protein (polypeptide) may be used that contains an amino acid sequence that is 80% or more, preferably 85% or more, more preferably 90% or more, even more preferably 95% or more, and particularly preferably 98% or more identical to the amino acid sequence shown in SEQ ID NO: 4, and that can promote cell membrane expression of olfactory receptors. It should be noted that, as long as it can promote the expression of olfactory receptors on the cell membrane, amino acid residues of other proteins (polypeptides) may be used in addition to bovine rhodopsin.

[0027] The method for measuring the response of olfactory receptors is not particularly limited, and any method used in the art can be used. For example, it is known that when an aroma compound binds to an olfactory receptor, it activates intracellular G protein, which then activates adenylate cyclase, converting ATP to cyclic AMP (cAMP), thereby increasing the amount of cAMP in the cell. Therefore, the response of olfactory receptors can be measured by measuring the amount of cAMP. Methods for measuring the amount of cAMP include ELISA and reporter gene assays. Among these, it is preferable to measure the response of olfactory receptors using a reporter gene assay using a luminescent substance such as luciferase.

[0028] <Process (ii)> In step (ii), the response of the olfactory receptor used in step (i) is measured in the absence of a malodor-causing substance. The method for measuring the olfactory receptor response can be the same as the method shown in step (i), except that the olfactory receptor is not brought into contact with the malodor-causing substance. For example, the olfactory receptor response may be measured on cells isolated from an organism expressing the olfactory receptor, or on cells in which the olfactory receptor is artificially expressed by genetic manipulation. In order to appropriately compare the measurement results in steps (i) and (ii), it is preferable that the measurement conditions in steps (i) and (ii) are the same, except for the presence or absence of contact with the malodor-causing substance.

[0029] <Step (iii)> In step (iii), the measurement results in steps (i) and (ii) are compared to calculate the change in responsiveness. According to one embodiment of the present invention, the change in responsiveness may be evaluated using as an index the fold increase value obtained by dividing the measurement result in step (i) by the measurement result in step (ii). For example, when measuring the response of olfactory receptors by a reporter gene assay method using a luminescent substance such as luciferase, the responsiveness can be evaluated using a concentration of the malodor-causing substance that results in a fold increase value of preferably 2 or more, more preferably 4 or more, and even more preferably 10 or more.

[0030] <Process (iv)> In step (iv), the test substance is mixed with the malodor-causing substance in step (i), and the change in response is calculated in the same manner as in step (iii).

[0031] <Process (v)> In step (v), test substances that show a reduced value in step (iv) compared to step (iii) are selected as candidates for malodor-controlling materials. In the present invention, when the measurement results in steps (iii) and (iv) are compared and a reduction in the change in responsiveness is observed, the test substance used in step (iv) can be evaluated as a candidate substance for an odor-suppressing material.

[0032] In this way, candidate substances for malodor-suppressing materials can be screened from among the test substances. According to the present invention, candidate substances for malodor-suppressing materials can be selected from a large number of test substances without problems such as olfactory fatigue and individual differences that arise from sensory evaluations based on the human sense of smell. The selected substances can be used as candidate substances for malodor-suppressing materials. Based on the selected substances, modifications can be made as necessary to develop novel compounds with optimal odors. Furthermore, the selected substances can be blended with other fragrance materials to develop fragrance materials that suppress malodors and have optimal odors. Use of the screening method of the present invention can contribute to the development of new fragrance materials for malodor-suppressing materials. [Example]

[0033] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0034] [Example 1] Confirmation that the olfactory receptor OR2L3 responds to malodor-causing substances (1) Cloning of olfactory receptor genes The human olfactory receptor gene was obtained by PCR cloning from Human Genomic DNA: Female (Promega) based on the sequence information registered in GenBank. The N-terminal 20 amino acid residues of bovine rhodopsin were inserted into the pME18S vector, and the obtained human olfactory receptor gene was inserted downstream to obtain a human olfactory receptor gene expression vector. (2) Expression of olfactory receptor genes in HEK293T cells A gene solution (per well) was prepared by dissolving 0.05 μg of the human olfactory receptor gene expression vector, 0.01 μg of the RTP1S vector, 0.01 μg of the firefly luciferase vector pGL4.29 (Promega) containing a cAMP response element promoter, and 0.005 μg of the Renilla luciferase vector pGL4.74 (Promega) containing a thymidine kinase promoter in 10 μL of Opti-MEM I (Gibco). HEK293T cells were seeded in 100 μL aliquots into 96-well plates (Biocoat, Corning) at a cell number that reached confluence after 24 hours. The gene solution was added to each well using the Lipofectamine 3000 lipofection method according to the manufacturer's instructions. The cells were then cultured at 37°C in a 5% CO atmosphere for 24 hours. (3) Luciferase reporter gene assay After removing the culture medium, 50 μL of a sample of aroma compounds prepared in CD293 (Gibco) medium (supplemented with 20 μM L-glutamine) at the concentration required for measurement was added to each well. After 3 hours of stimulation, luciferase activity was measured according to the instructions for the Dual-Luciferase Reporter Assay System (Promega). The response strength of the olfactory receptor was expressed as the fold increase value, calculated by dividing the luciferase activity generated by stimulation with the aroma compound by the luciferase activity generated in a test system without the aroma compound. (4) Identification of olfactory receptors that respond to malodorous substances The response of the olfactory receptor OR2L3 to representative malodor-causing substances, skatole, indole, α-terpineol, 4-terpineol, and p-methylacetophenone, was measured at various concentrations using a luciferase reporter gene assay. The results are shown in Figures 1 to 5. OR2L3 showed a concentration-dependent response to various malodor-causing substances. However, no response was observed in a mock test (using cells that do not express OR2L3). This indicates that OR2L3 responds specifically to various malodor-causing substances.

[0035] [Example 2] Evaluation of the response suppression effect of OR2L3 to odor-suppressing materials In Patent Document 4, cis-3-hexenyl hexanoate, known as a skatole odor-suppressing material that masks the skatole odor, was used to measure its effect of suppressing the response of OR2L3, which showed a strong response to skatole, using a luciferase reporter gene assay. In the luciferase reporter gene assay, a mixture of skatole and cis-3-hexenyl hexanoate was used as the sample, and the fold increase value in the test in which cis-3-hexenyl hexanoate was added was calculated as the ratio of the fold increase value in the test in which cis-3-hexenyl hexanoate was added to the fold increase value in the test in which cis-3-hexenyl hexanoate was not added, defined as 100. The results are shown in Figure 6. This demonstrates the effect of cis-3-hexenyl hexanoate in reducing the response of OR2L3 to skatole in a concentration-dependent manner.

[0036] [Example 3] Evaluation of the response suppression effect of OR2L3 to odor suppression materials (candidate substance group) For the malodor-suppressing materials (candidate substance group) including Group A shown in Table 1, the effect of suppressing the response of OR2L3, which showed a strong response to malodors, was measured using a luciferase reporter gene assay. In the luciferase reporter gene assay, a mixture of skatole and Guavacore (registered trademark) was used as the sample, and the fold increase value in the test without guavacore was set to 1. The ratio of the fold increase value in the test with guavacore was calculated. The results are shown in Figure 7. The effect of guavacore on reducing the response of OR2L3 to skatole in a concentration-dependent manner was demonstrated. A similar test was conducted to evaluate the response-inhibitory effect of OR2L3, substituting Dextran Bar (registered trademark) for guavacore. The results are shown in Figure 8. The effect of Dextran Bar in reducing the response of OR2L3 to skatole in a concentration-dependent manner was demonstrated. A similar test was conducted, substituting Hinginol (registered trademark) for guavacore. The results are shown in Figure 9. The effect of Hinginol in reducing the response of OR2L3 to skatole in a concentration-dependent manner was demonstrated. The same test was conducted to evaluate the response-inhibitory effect of OR2L3, replacing skatole with indole. The results for Group A, where guavacoa, dextran bar, or hingenol were used, are shown in Figures 10 to 12. The effect of guavacoa, dextran bar, and hingenol on the response of OR2L3 to indole was concentration-dependently reduced. The response-inhibitory effect of OR2L3 was also evaluated by replacing guavacore with Group A, and replacing the malodor with α-terpineol, 4-terpineol, or p-methylacetophenone. In all cases, Group A demonstrated a concentration-dependent reduction in the OR2L3 response to each malodor. [Table 1]

[0037] [Example 4] Evaluation of odor suppression ability of Group A The malodor-suppressing ability of test substances with receptor activity inhibitory activity was confirmed by sensory evaluation. As malodors, 10 μL each of skatole diluted 100-fold with triethyl citrate or indole diluted 100-fold was dropped, and a cotton ball with 1 μL of the test substance was dropped on it was placed in a plastic bottle (Takemoto Container OZO-40). The bottle was left to stand at room temperature for 1 hour to allow the odor molecules to fully volatilize in the bottle. The sensory evaluation test was conducted by a panel of 20 people, and the odor intensity when the malodor was dropped alone was rated as 8, and the odor intensity when the test substance was mixed was rated from 0 (no malodor perceived) to 10 (very strong malodor perceived). The average value was calculated from the obtained values. The results are shown in Table 2. Humes Ether (registered trademark), which inhibits the skatole response of OR2L3, significantly reduced the intensity of skatole odor. This inhibition of skatole was more pronounced than when control substances (4-t-butylcyclohexanol and hexyl salicylate) were used, which did not inhibit the skatole response of OR2L3. Furthermore, when we examined indole, we also found that humes ether suppressed the intensity of indole odor. We also tested the odor-suppressing effects of other substances that inhibit OR2L3 responses (guavacoa, panprex, ambrette, dextran bar, hingol, lingol (all registered trademarks), cardamom oil, clary sage oil, mandarin oil, and spearmint oil), and found that all of these substances suppressed the respective odors.

[0038] [Table 2] As described above, by using the screening method of the present invention, it was possible to select candidate substances for malodor-controlling materials from among a large number of test substances. [Industrial Applicability]

[0039] By using the screening method of the present invention, candidate substances for malodor-suppressing materials can be selected from a large number of test substances, and it is expected that the screening method of the present invention will contribute to the development of malodor-suppressing materials.

Claims

1. 1. A method for screening malodor control materials, comprising the steps of: adding a test substance and a malodor-causing substance to an olfactory receptor polypeptide selected from the group consisting of an olfactory receptor polypeptide OR2L3 consisting of the amino acid sequence (SEQ ID NO: 2) and a polypeptide comprising an amino acid sequence having at least 90% identity with the amino acid sequence of OR2L3 and exhibiting responsiveness to a malodor-causing substance; Measuring the response of the olfactory receptor polypeptide to a malodor-causing substance; and identifying a test substance that inhibits the response of the olfactory receptor polypeptide based on the measured response as a candidate malodor-controlling material; Including, The method, wherein the malodor is skatole odor, indole odor, α-terpineol odor, 4-terpineol odor, or p-methylacetophenone odor.

2. 2. The method according to claim 1, wherein the malodor is fecal odor, bad breath, stagnant odor from dairy products, or stagnant odor from citrus fruits.

3. 2. The method of claim 1, wherein said malodor is an odor caused by a compound, composition or mixture that is unpleasant to humans.

4. The method according to any one of claims 1 to 3, wherein the response of the olfactory receptor polypeptide to a malodor-causing substance is measured on cells isolated from an organism expressing the olfactory receptor, or on cells in which the olfactory receptor is artificially expressed by genetic manipulation.

5. The method according to any one of claims 1 to 4, wherein the response of the olfactory receptor is measured by a reporter gene assay or calcium imaging.

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