JPH0665013A - Antimicrobial protein - Google Patents

Abstract

PURPOSE:To provide an antimicrobial protein which is prepared by allowing a protein to adsorb silver and shows strong antimicrobial activity with high safety. CONSTITUTION:A variety of proteins, particularly hard protein and vegetable protein are mixed with a variety of silver solutions and recovered by filtration or precipitation with a solvent, washing off the free silver with water or a solvent and dried to give the objective antimicrobial protein. The content of the silver is suitably 0.005 to 10wt.% based on the protein weight. The antimicrobial protein shows high chemical, physical and biological safeties giving no damage to the properties of the original protein and the antimicrobial properties by silver and can be utilized over a wide range of applications.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an antibacterial protein.

[0002]

2. Description of the Related Art Animal and soybean such as chicken, cow, pig, silkworm,
Various plant-derived proteins such as corn and wheat are widely used in foods, cosmetics, pharmaceuticals, industrial products and the like. These proteins are generally unstable to the environment, particularly microorganisms, and microbial contamination of the protein itself or a product containing the protein is a problem. Further, it is well known that some proteins and peptides, which are degradation products of proteins, have antibacterial properties, but their effects are weak and their application range is narrow.

Metal ions such as silver ions, copper ions,
It is a known fact that zinc ions and the like have antibacterial properties, and particularly silver ions have strong antibacterial properties and are widely used as disinfectants and bactericides in the form of an aqueous solution of silver nitrate. However, the solution form was inconvenient to handle and had limited uses. part,
Although an inorganic antibacterial agent in which silver ions are adsorbed on an inorganic substance such as silica gel or zeolite is disclosed, it is only used for industrial purposes such as resins, paints and papermaking. (JP-A-6
0-100504, JP-A-63-265809, JP-A-3-193701). It is also reported that a gelatin solution containing silver ions was used for the treatment of diseases such as eyes, ears and nose. (27th. "The United States Dispensatory"
However, this substance is insoluble in water and very unstable, which makes it inconvenient to handle.

[0004]

From the above,
There is a strong demand for novel antibacterial proteins that have antibacterial properties themselves, are highly effective, and have high stability in order to expand their applications.

[0005]

[Means for Solving the Problems] As a result of intensive research to solve the above problems, it was found for the first time that various proteins, particularly hard protein and vegetable protein, have a strong antibacterial property against which silver is adsorbed. The invention was completed. That is, the present invention provides an antibacterial protein having silver adsorbed on the protein. Hereinafter, the present invention will be described in detail.

The protein of the present invention is a hard protein such as eggshell membrane, feather, wool, silk and collagen, silk fibroin, elastin and the like separated from them. These hard proteins are fibrous proteins that are insoluble in water, salt solutions and other solvents, and are very stable proteins. Further, as the protein of the present invention, vegetable protein such as soybean, corn and wheat, its degradation product or purified product can be used.

As the silver of the present invention, silver nitrate, silver sulfate, silver perchlorate, silver oxide, silver chloride, diammine silver nitrate, diammine silver sulfate and the like can be used.

The method for producing the antibacterial protein of the present invention is extremely simple. That is, after being mixed with the above various silver solutions to be adsorbed, they are recovered by filtration or solvent precipitation. After that, non-adsorbed silver is washed off with water or a solvent and dried to obtain the product of the present invention. The solvent used can be appropriately selected depending on the type of silver compound.

From the viewpoint of antibacterial property, the content of silver to be adsorbed on various proteins is preferably 0.005-10% with respect to the weight of the protein.

The antibacterial protein thus obtained does not impair the properties of the protein and the antibacterial property of silver, and is very stable chemically, physically and biologically. It can be used in a wide range of fields.

The present invention will be described below with reference to examples and test examples, but the present invention is not limited thereto.

【Example】

Example 1 100 g of eggshell membrane powder (average particle size 10 μm) obtained from chicken eggs was added to 500 ml of 0.2% silver nitrate aqueous solution, stirred for 10 minutes, filtered, washed with water until non-adsorbed silver was eliminated, and finally with acetone. After dehydration and drying, 101 g of the antibacterial protein of the present invention was obtained. The silver content per egg shell membrane weight was 0.4% as determined by atomic absorption spectrometry.

Example 2 100 g of collagen powder (average particle size 10 μm) purified from cowhide was added to 500 ml of 0.2% silver nitrate aqueous solution, stirred for 5 minutes, filtered, washed with water until non-adsorbed silver was eliminated, and finally with acetone. Dehydrated and dried in an antibacterial protein 95 of the present invention
g was obtained. The silver content per collagen weight was 0.11% as measured by atomic absorption spectrometry.

Example 3 To 500 ml of 0.2% silver nitrate aqueous solution, 100 g of zein powder separated from corn was added, stirred for 10 minutes, filtered, washed with water until the non-adsorbed silver disappeared, and finally dehydrated and dried with acetone. 105 g of the antibacterial protein of the present invention was obtained.
The silver content per egg shell membrane weight was 0.18% as measured by atomic absorption spectrometry.

Test Example 1. Antibacterial Test The antibacterial tests of the antibacterial proteins obtained in Examples 1 and 2 were carried out by the following method. Mold as a test strain; Asperigillus nigar ATCC3275
), Aureobasidium pullulans
pullulans IFO6353), Penicillium citrusnum (P
enicillium citrinum IFO7784), Trycophyton mentagrophytes IFO58
09), yeast; Saccharomyces cerevisiae (Saccharo
myces cerevisiae IFO0203), Candida albicans IFO1061), bacteria; Bacillus
Subtilis (Bacillus subtilis IFO3007), Staphylococcus aureus IFO1
2732), Pseudomonas aeruginosa (Pseudomona
s aeruginosa IFO3080), Escheria coli (Escher
icia coli IFO3545), Streptococcus mutans MT8148, Bacteroides gingivalis ATCC3
3277), Propionibacterium acnes (Propioni
bacterium acnes GAI5419) was used to determine the minimum inhibitory concentration (%) by the agar dilution method. The medium used is mold,
Yeast is YM agar (Difco), and bacteria are standard agar (Eiken) or GAM agar (Eiken).

An agar medium containing samples of various concentrations was prepared,
On the agar, one platinum loop was inoculated with the bacterial solution of each strain that had been previously cultured in a culture medium for enrichment, and the cells were cultured under each condition. After the culture, the minimum growth inhibitory concentration was measured from the growth state of the bacteria. The results are shown in Table 1.

[0016]

[Table 1]

Test Example 2. Hygroscopicity test The hygroscopicity originally possessed by the eggshell membrane powder used in Example 1 and the hygroscopicity of the antibacterial protein obtained in Example 1 were examined.
A sample that has been dried and weighed in advance has
It was left in a desiccator (5, 80, 90%) for 3 days and nights, the weight after moisture absorption was measured, and the moisture absorption rate was calculated from the difference from the following formula. Moisture absorption rate = (moisture absorption weight-dry weight) / dry weight x 100 The results are shown in Table 2.

[0018]

[Table 2]

Test Example 3. Stability test The antibacterial protein obtained in Example 1 was stored for a long period of time, and the antibacterial property and the degree of coloring were examined. As a result of storing the antibacterial protein at room temperature for half a year and further for one year, the antibacterial property was maintained and neither coloring nor spoiled odor was observed.

From the above results, the antibacterial protein of the present invention in which silver is adsorbed on various proteins has excellent antibacterial properties, and also has properties inherent to these proteins such as hygroscopicity and long-term stability. It was shown to be excellent.

[0021]

The various proteins used in the present invention are extremely safe because they are materials used in the fields of food and cosmetics in large quantities. Therefore, the antibacterial protein in which silver is adsorbed to these proteins is also highly safe, has excellent antibacterial properties and stability, and has properties inherent in the proteins. Furthermore, since its manufacturing method is extremely simple, it can be applied to various fields such as industrial, medical, cosmetics and food.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kim Takehisa 9-5 Akahorishinmachi, Yokkaichi-shi, Mie Taiyo Kagaku Co., Ltd.

Claims (3)

[Claims] 1. An antibacterial protein in which silver is adsorbed on the protein. 2. The antibacterial protein according to claim 1, wherein the protein is a hard protein. 3. The antibacterial protein according to claim 1, wherein the protein is a vegetable protein.