Reagents and processes for stabilizing alkaline phosphatase or conjugates thereof
View Patent ↗The present disclosure relates to stabilizers for alkaline phosphatase or conjugates thereof, a process for preparing a stabilizer, and a method for stabilizing alkaline phosphatase or conjugates thereof with a stabilizer. The present disclosure also relates to a reagent of alkaline phosphatase or conjugates thereof as well as to a process for preparing the same. In another aspect, the present disclosure relates to a kit comprising the stabilizers disclosed herein and alkaline phosphatase or conjugates thereof. The stabilizer disclosed herein can stabilize alkaline phosphatase or conjugates thereof for a prolonged period of time, extending their shelf-life.
1. A method for stabilizing alkaline phosphatase or a conjugate thereof, the method comprising:
mixing alkaline phosphatase or a conjugate thereof with an aqueous alkaline phosphatase stabilizer solution;
wherein the aqueous alkaline phosphatase stabilizer solution comprises:
a protein selected from at least one of the following: albumin, casein, and gelatin;
magnesium and calcium ions, wherein the magnesium and calcium ions together have a concentration in the range of between about 0.001 and about 0.01mol/L;
zinc ions, wherein the zinc ions have a concentration in the range of between about 0.01 and about 0.2 mmol/L; and
sodium ions, wherein the sodium ions have a concentration in the range of between about 0.5 and about 3.0 mol/L.
2. The method of claim 1 , wherein the sodium ions in the aqueous alkaline phosphatase stabilizer solution are derived from sodium chloride.
3. The method of claim 2 , wherein the aqueous alkaline phosphatase stabilizer solution contains from about 30 g/L to about 175 g/L of sodium chloride.
4. The method of claim 1 , wherein the aqueous alkaline phosphatase stabilizer solution further comprises one or more protectant, wherein the one or more protectant is selected from at least one of the following: a polyol, a saccharide, a surfactant and a polyethylene glycol.
5. The method of claim 4 , wherein the polyol is selected from at least one of the following: glycerol, mannitol, sorbitol, inositol and xylitol.
6. The method of claim 4 , wherein the saccharide is selected from at least one of the following: galactose, lactose, fructose, sucrose, and trehalose.
7. The method of claim 4 , wherein the surfactant is a nonionic surfactant.
8. The method of claim 7 , wherein the nonionic surfactant is either a sorbitan polyoxyethylene ether fatty acid ester or an alkylphenol polyoxyethylene ether.
9. The method of claim 8 , wherein the sorbitan polyoxyethylene ether fatty acid ester is either a sorbitan polyoxyethylene ether lauric acid ester or a sorbitan polyoxyethylene ether oleic acid ester.
10. The method of claim 8 , wherein the alkylphenol polyoxyethylene ether is an octylphenol polyoxyethylene ether.
11. The method of claim 4 , wherein the polyethylene glycol has a molecular weight ranging from about 6,000 to about 20,000.
12. The method of claim 11 , wherein the polyethylene glycol has a molecular weight of about 20,000.
13. The method of claim 1 , wherein the aqueous alkaline phosphatase stabilizer solution further comprises a buffering agent.
14. The method of claim 1 , wherein the aqueous alkaline phosphatase stabilizer solution further comprises a protease inhibitor.
15. A process for preparing a reagent of alkaline phosphatase or a conjugate thereof, the process comprising:
mixing or dissolving alkaline phosphatase or a conjugate thereof in an aqueous alkaline phosphatase stabilizer solution;
wherein the aqueous alkaline phosphatase stabilizer solution comprises:
a protein selected from at least one of the following: albumin, casein, and gelatin;
magnesium and calcium ions, wherein the magnesium and
calcium ions together have a concentration in the range of between about 0.001 and about 0.01 mol/L;
zinc ions, wherein the zinc ions have a concentration in the range of between about 0.01 and about 0.2 mmol/L;
sodium ions, wherein the sodium ions have a concentration in the range of between about 0.5 and about 3.0 mol/L; and
a nonionic surfactant, wherein the nonionic surfactant is an octylphenol polyoxyethylene ether type surfactant that is present in a concentration in the range of
between about 0.1% and about 10% (w/v); and
optionally drying the solution into a powder.
16. A process for preparing a reagent of alkaline phosphatase or a conjugate thereof, the process comprising:
drying an aqueous alkaline phosphatase stabilizer solution to a powder;
drying an aqueous solution of alkaline phosphatase or a conjugate thereof to a powder; and
mixing the powders together;
wherein the aqueous alkaline phosphatase stabilizer solution comprises:
a protein selected from at least one of the following: albumin, casein and gelatin;
magnesium and calcium ions, wherein the magnesium and
calcium ions together have a concentration in the range of between about 0.001 and about 0.01 mol/L;
zinc ions, wherein the zinc ions have a concentration in the range of between about 0.01 and about 0.2 mmol/L;
sodium ions, wherein the sodium ions have a concentration in the range of between about 0.5 and about 3.0 mol/L; and
a combination of glycerol and mannitol, wherein the combined concentration of glycerol and mannitol is between about 5% and about 10% (w/v).