Method for extending light-emitting time of calcium-binding photoprotein solution
AssigneeJnc Corporation
InventorsSatoshi Inouye, Satoko Sasaki
Life of this patent
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Abstract
Methods for extending light-emitting time of a solution of a calcium-binding photoprotein that instantaneously emits light by binding to calcium ions are provided. In the light-emitting reaction system of a solution of a calcium-binding photoprotein, a light-emitting reaction is performed in the presence of an anion capable of binding to the calcium ion or the cation that can be substituted for the calcium ion and/or a cation that can bind to the calcium-binding site of the calcium-binding photoprotein with a lower affinity than the calcium ion or the cation that can be substituted for the calcium ion without activating the calcium-binding photoprotein.
Claims14
A method for extending light-emitting time of a solution comprising (a) a calcium-binding photoprotein that requires a calcium ion for producing luminescence and that is composed of an apoprotein and peroxide of coelenterazine or analog thereof and (b) a calcium ion, cadmium ion, and/or lead ion, the method comprising:
- (i) providing a solution comprising the calcium-binding photoprotein wherein the concentration of the calcium-binding photoprotein is 0.01 mg/ml to 10 mg/ml;
- (ii) stirring a magnesium ion or a zinc ion with the solution in (i) such that the concentration of the magnesium ion after stirring is 10 mM or more or the concentration of the zinc ion after stirring is 600 mM or more;
- (iii) stirring a calcium ion, cadmium ion, and/or lead ion with the solution comprising the calcium-binding photoprotein such that the concentration of the calcium ion or another cation that can be substituted for the calcium ion is 10−7 mole/liter or more;
- and
- (iv) allowing a reaction between (a) and (b) to proceed in the solution obtained in (iii);
- wherein during the light-emitting time, (a) binds to (b) to bring about oxidation of the peroxide of a coelenterazine or an analog thereof, resulting in the release of a coelenteramide or an analog thereof from the apoprotein.
A method of extending light-emitting time of a solution comprising (a) a calcium-binding photoprotein that requires a calcium ion for producing luminescence and that is composed of an apoprotein and peroxide of coelenterazine or analog thereof and (b) a calcium ion cadmium ion, and/or lead ion, the method comprising:
- (i) providing a solution comprising the calcium-binding photoprotein wherein the concentration of the calcium-binding photoprotein is 0.01 mg/ml to 10 mg/ml;
- (ii) stirring a sulfate ion and either a magnesium ion or a zinc ion with the solution in (i) such that the concentration of the sulfate ion after stirring is 300 mM or more and the concentration of the magnesium ion after stirring is 5 mM or more or the concentration of the zinc ion after stirring is 600 mM or more;
- (iii) stirring a calcium ion, cadmium ion, and/or lead ion with the solution comprising the calcium-binding photoprotein such that the concentration of the calcium ion or another cation that can be substituted for the calcium ion is 10−7 mole/liter or more;
- and
- (iv) allowing a reaction between (a) and (b) to proceed in the solution obtained in (iii);
- wherein during the light-emitting time, (a) binds to (b) to bring about oxidation of the peroxide of a coelenterazine or an analog thereof, resulting in the release of a coelenteramide or an analog thereof from the apoprotein.
A method for extending light-emitting time of a solution comprising (a) a calcium-binding photoprotein that requires a calcium ion for producing luminescence and that is composed of an apoprotein and peroxide of coelenterazine or analog thereof and (b) a calcium ion cadmium ion, and/or lead ion, the method comprising:
- (i) providing a solution comprising the calcium-binding photoprotein wherein the concentration of the calcium-binding photoprotein is 0.01 mg/ml to 10 mg/ml;
- (ii) stirring magnesium sulfate, magnesium chloride, zinc sulfate, zinc chloride, or strontium chloride, with the solution in (i) such that the concentration of magnesium sulfate after stirring is 10 mM or more, the concentration of magnesium chloride after stirring is 300 mM or more, the concentration of zinc sulfate after stirring is 600 mM or more, the concentration of zinc chloride after stirring is 600 mM or more, or the concentration of strontium chloride after stirring is 600 mM or more;
- and
- (iii) stirring a calcium ion, cadmium ion, and/or lead ion with the solution comprising the calcium-binding photoprotein such that the concentration of the calcium ion or another cation that can be substituted for the calcium ion is 10−7 mole/liter or more;
- (iv) allowing a reaction between (a) and (b) to proceed in the solution obtained in (iii);
- wherein during the light-emitting time, (a) binds to (b) to bring about oxidation of the peroxide of a coelenterazine or an analog thereof, resulting in the release of a coelenteramide or an analog thereof from the apoprotein.
Dependencies are inferred from the claim text.