Panasonic clarifies the mechanism of cedar pollen allergen^*1 inactivation by gaseous hypochlorous acid

- Panasonic proposes the inhibitory effect on various protein-based allergens

Osaka, Japan, February 28, 2025 – Panasonic Corporation today announced that its Heating & Ventilation A/C Company clarified the mechanism of cedar pollen allergen inactivation by gaseous hypochlorous acid, jointly with ITEA Inc., Institute of Tokyo Environmental Allergy.*² This suggests that the same inactivation mechanism can also be applied to other protein-based allergens.

The prevalence of hay fever, a common allergic disease, has been increasing in Japan every year, with rates recorded at 19.6% in 1998, 29.8% in 2008, and 42.5% in 2019.*³ Cedar pollen allergens, to which approximately 90% of hay fever patients have an allergic reaction,*³ include Cry j 1 adhered to the surface of the pollen outer wall, and Cry j 2, which is present inside the pollen grain and is emitted when the outer wall is broken. It has been revealed that they are composed of proteins, similar to mold and mite allergens.

Since adopting the hypochlorous acid solution*⁴ for the hygiene maintenance system of cup-dispensing vending machines in 1987, Panasonic has been researching hypochlorous acid technology for approximately 40 years*⁵ and conducted various tests to verify bacterial and viral inhibition and deodorization. Although the company has verified that hypochlorous acid inactivates the Cry j 1 cedar pollen allergen, its mechanism had not yet been clarified.

During ongoing joint research, Panasonic exposed the Cry j 1 cedar pollen allergen to gaseous hypochlorous acid by using a dedicated device to verify whether changes in the amino acid sequences of proteins present in Cry j 1 would be observed. As a result, the random split of peptide bonds*⁶ formed between amino acids was confirmed. The company revealed that this phenomenon inactivated Cry j 1, and that the antigenicity causing allergy symptoms was no longer detected.

Regarding the current verification results, Director Masahiro Sakaguchi of the Institute of Tokyo Environmental Allergy, ITEA Inc., and Professor Emeritus at Azabu University, commented, "Based on the inactivation mechanism of the Cry j 1 cedar pollen allergen identified through current research, I infer that if other problematic indoor allergens are also composed of proteins, they will be inactivated by similar mechanisms. I believe that these verification efforts bear significant meaning for the future development of allergy-related research."

Panasonic will engage in research on hypochlorous acid technology to create a space, where people can live with a sense of security and safety.

Notes:

*1: Substance causing allergy symptoms

*2: These verifications were conducted for basic research purposes and did not involve any products.

*3: Hay Fever Environmental Health Manual 2022, Ministry of the Environment (https://www.env.go.jp/chemi/anzen/kafun/2022_full.pdf) *Japanese only

*4: Solution made by electrolysis of salt water

*5: Including the SANYO Electric era

*6: Covalent bond formed by alpha-amino acids through dehydration and condensation

Details of verification

Figure 1. Overview of a gaseous hypochlorous acid exposure device

Verifying organization: Heating & Ventilation A/C Company, Panasonic Corporation
Testing organization: Panasonic Holdings Corporation, Product Analysis Center (ELISA, electrophoresis)
ITEA Inc., Institute of Tokyo Environmental Allergy (dot blotting)
Pharma Foods International Co., Ltd., Apro Science Group (LC-MS/MS)
Test subject: Cry j 1, purified Japanese cedar pollen allergen
Verifying device: Gaseous hypochlorous acid (approx. 50 ppb) volatilized from the sodium hypochlorite solution (pH 8) was ventilated through the bio-column (50 mm in diameter, 130 mm long) to bring it into contact with Cry j 1 placed in the bio-column. Simultaneously, a control sample without exposure to gaseous hypochlorous acid was prepared. (Figure 1)
Contact method: The plate, to which Cry j 1 was applied and dried, was placed in the bio-column. Then, gaseous hypochlorous acid was ventilated through the bio-column and remained in contact with the allergen. Subsequently, the supply of gaseous hypochlorous acid was stopped, the column was opened, and the plate coated with Cry j 1 was removed.

Verification results

Figure 2. Antigenic detection by dot blotting (Exposure for 1 hour)
(proprietary technology of ITEA Inc., Patent No. 7126665)
The inactivation of Cry j 1 was verified by detecting the presence of proteins in the specimen using the colloidal gold staining and confirming the loss of antigenicity by immunostaining.

(1) Cry j 1 was inactivated by contact with gaseous hypochlorous acid. (Figures 2 and 3)

(2) The molecular weight of Cry j 1 was altered by contact with gaseous hypochlorous acid. (Figure 4)

(3) The peptides of amino acids in Cry j 1 were randomly split. (Table 1)

Figure 3. Results of the Cry j 1 inactivation test by ELISA
When exposed to gaseous hypochlorous acid, the sample showed a sharp drop in the amount of Cry j 1, confirming the allergen's inactivation, while the sample that was not exposed did not exhibit any changes in the amount of Cry j 1 even after three hours.

Figure 4. Molecular weight determination by electrophoresis
(M: Molecular weight marker, a: 0 hours, b: Non-exposure (24 hours), c: Exposure to gaseous hypochlorous acid (24 hours))
While the control sample showed a band at the position corresponding to the molecular weight of Cry j 1 even after 24 hours, the sample exposed to gaseous hypochlorous acid did not exhibit a band in the same position. This confirmed a change in molecular weight.

Table 1. Amino acid sequences observed in Cry j 1 when exposed to gaseous hypochlorous acid (LC-MS/MS)
(The letters specified in the above table indicate the single-letter symbol for each amino acid.)
Twenty-six types of random peptide fragments were observed. It was confirmed that a total of 18 amino acids were present at the end of peptides, and peptides were broken at random intervals.

About the Panasonic Group

Founded in 1918, and today a global leader in developing innovative technologies and solutions for wide-ranging applications in the consumer electronics, housing, automotive, industry, communications, and energy sectors worldwide, the Panasonic Group switched to an operating company system on April 1, 2022 with Panasonic Holdings Corporation serving as a holding company and eight companies positioned under its umbrella. The Group reported consolidated net sales of 8,496.4 billion yen for the year ended March 31, 2024. To learn more about the Panasonic Group, please visit: https://holdings.panasonic/global/

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