Norovirus deactivator and method for producing same, method for deactivating norovirus, method for producing lysozyme component for norovirus deactivation use, prophylactic or therapeutic agent for norovirus infection, and external preparation for skin for norovirus deactivation purposes

Abstract

Provided is a norovirus deactivator, including a lysozyme component that includes at least one kind selected from lysozyme and/or a salt thereof, and a denatured product thereof.

1 . A norovirus deactivator, comprising a lysozyme component that comprises at least one kind selected from lysozyme and/or a salt thereof, and a denatured product thereof. 
     
     
         2 . The norovirus deactivator according to  claim 1 , wherein a content of the lysozyme component is 0.05 mass % or more. 
     
     
         3 . The norovirus deactivator according to  claim 1 , wherein the lysozyme component has a fluorescence intensity specified by the following definition of 4,000 or more:
 Fluorescence intensity: a fluorescence intensity measured under conditions of an excitation wavelength of 390 nm with an excitation band width of 10 nm, a fluorescence wavelength of 470 nm with a fluorescence band width of 10 nm for a liquid obtained by adding 25 μL of a methanol solution of 8 mM 1,8-anilinonaphthalenesulfonic acid to 5 mL of a dilution obtained by diluting the lysozyme component with a phosphate buffer having a pH of 7.0 so as to have a concentration of the lysozyme component of 0.05 mass % in terms of solid content, and to have a concentration of phosphate of 0.2 M and then subjecting the liquid is subjected to a reaction at room temperature for 30 minutes.   
     
     
         4 . The norovirus deactivator according to  claim 1 , wherein the lysozyme component has an anti-norovirus activity specified below of 2.0 or more:
 Anti-norovirus activity: a value obtained by subtracting, when a norovirus mixed liquid obtained by mixing equal amounts of a norovirus solution and a 2 mass % aqueous solution of the lysozyme component is left standing at room temperature for 1 minute, a logarithm of an infectivity titer after the standing from a logarithm of an infectivity titer before the standing.   
     
     
         5 . The norovirus deactivator according to  claim 1 , wherein the norovirus deactivator comprises a liquid formulation. 
     
     
         6 . A method of deactivating norovirus, the method comprising deactivating norovirus using a lysozyme component that comprises at least one kind selected from lysozyme and/or a salt thereof, and a denatured product thereof. 
     
     
         7 . A method of producing a lysozyme component for norovirus deactivation use to be incorporated into the norovirus deactivator of  claim 1 , the method comprising thermally denaturing lysozyme and/or a salt thereof. 
     
     
         8 . A method of producing a norovirus deactivator, the method comprising incorporating a lysozyme component that comprises at least one kind selected from lysozyme and/or a salt thereof, and a denatured product thereof. 
     
     
         9 . The method of producing a norovirus deactivator according to  claim 8 , further comprising: thermally denaturing the lysozyme and/or the salt thereof to obtain a thermally denatured product; and obtaining a norovirus deactivator containing the thermally denatured product. 
     
     
         10 . The method of producing a norovirus deactivator according to  claim 9 , wherein the obtaining the thermally denatured product comprises:
 a first heating step of heating an aqueous solution of the lysozyme and/or the salt thereof having a transmittance for light having a wavelength of 660 nm of more than 70%, a pH of 5.0 or more and 7.0 or less, and a concentration of the lysozyme and/or the salt thereof of 0.5 mass % or more and 7 mass % or less in terms of solid content, until the transmittance of the aqueous solution for light having a wavelength of 660 nm becomes 70%;   after the first heating step, a second heating step of heating the aqueous solution until the transmittance of the aqueous solution for light having a wavelength of 660 nm reaches a minimum of less than 70%, followed by heating of the aqueous solution until the transmittance becomes 70%; and   after the second heating step, a third heating step of further heating the aqueous solution in a state in which the transmittance of the aqueous solution for light having a wavelength of 660 nm is more than 70%.   
     
     
         11 . The method of producing a norovirus deactivator according to  claim 10 , wherein heating conditions of the third heating step comprise such conditions that the heating is performed until a transmittance for light having a wavelength of 660 nm of a mixture of a product obtained by filtering the aqueous solution obtained in the third heating step through a 0.45 μm membrane filter with ethanol at a ratio of 1:1 in terms of mass ratio becomes 85% or more. 
     
     
         12 . The method of producing a norovirus deactivator according to  claim 10 , further comprising, after the third heating step, subjecting the aqueous solution to spray drying or freeze drying to obtain the denatured product in a powder form. 
     
     
         13 . A prophylactic agent or therapeutic agent for norovirus infection, comprising a lysozyme component that comprises at least one kind selected from lysozyme and/or a salt thereof, and a denatured product thereof. 
     
     
         14 . An external preparation for skin for norovirus deactivation purposes, comprising a lysozyme component that comprises at least one kind selected from lysozyme and/or a salt thereof, and a denatured product thereof. 
     
     
         15 . A lysozyme component for norovirus deactivation use, comprising at least one kind selected from lysozyme and/or a salt thereof, and a denatured product thereof. 
     
     
         16 . A prophylactic agent or therapeutic agent for acute viral gastroenteritis, comprising a lysozyme component that comprises at least one kind selected from lysozyme and/or a salt thereof, and a denatured product thereof. 
     
     
         17 . A method for preventing or treating acute viral gastroenteritis, comprising taking a lysozyme component that comprises at least one kind selected from lysozyme and/or a salt thereof, and a denatured product thereof 
     
     
         18 . The norovirus deactivator according to  claim 2 , wherein the lysozyme component has a fluorescence intensity specified by the following definition of 4,000 or more:
 Fluorescence intensity: a fluorescence intensity measured under conditions of an excitation wavelength of 390 nm with an excitation band width of 10 nm, a fluorescence wavelength of 470 nm with a fluorescence band width of 10 nm for a liquid obtained by adding 25 μL of a methanol solution of 8 mM 1,8-anilinonaphthalenesulfonic acid to 5 mL of a dilution obtained by diluting the lysozyme component with a phosphate buffer having a pH of 7.0 so as to have a concentration of the lysozyme component of 0.05 mass % in terms of solid content, and to have a concentration of phosphate of 0.2 M and then subjecting the liquid is subjected to a reaction at room temperature for 30 minutes.   
     
     
         19 . The norovirus deactivator according to  claim 2 , wherein the lysozyme component has an anti-norovirus activity specified below of 2.0 or more:
 Anti-norovirus activity: a value obtained by subtracting, when a norovirus mixed liquid obtained by mixing equal amounts of a norovirus solution and a 2 mass % aqueous solution of the lysozyme component is left standing at room temperature for 1 minute, a logarithm of an infectivity titer after the standing from a logarithm of an infectivity titer before the standing.   
     
     
         20 . The norovirus deactivator according to  claim 3 , wherein the lysozyme component has an anti-norovirus activity specified below of 2.0 or more:
 Anti-norovirus activity: a value obtained by subtracting, when a norovirus mixed liquid obtained by mixing equal amounts of a norovirus solution and a 2 mass % aqueous solution of the lysozyme component is left standing at room temperature for 1 minute, a logarithm of an infectivity titer after the standing from a logarithm of an infectivity titer before the standing.