Method for formulating a glucose oxidase enzyme with a desired property or properties and a glucose oxidase enzyme with the desired property

• US 20030077702A1
• Filed: 12/28/2001
• Published: 04/24/2003
• Est. Priority Date: 10/23/2001
• Status: Abandoned Application

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Shah, Rajiv, Reghabi, Bahar
• Application Number:
  US10/035,918
• Publication Number:
  US 20030077702A1
• Time in Patent Office: Days
• US Class Current: 435/69.1
• CPC Class Codes: C12N 9/0006 acting on CH-OH groups as donors (1.1)

Abstract

A method for formulating a glucose oxidase enzyme with peroxide resistant properties and a glucose oxidase enzyme formulated by the method. The enzyme formulation method results in a glucose oxidase enzyme with improve resistance to peroxide, and therefore, with improved resistance to oxidative inactivation. The method employs directed evolution techniques to evolve glucose oxidase to achieve the desirable properties. A peroxide resistant glucose oxidase may improve the longevity of, for example, glucose biosensors in which a peroxide resistant glucose oxidase may be placed.

Claims

1. A method for formulating an enzyme comprising:

obtaining at least one glucose oxidase gene;

creating at least one mutated glucose oxidase gene;

introducing each mutated glucose oxidase gene into separate expression vectors;

inserting the expression vectors into host organisms;

growing colonies of the host organisms; and

screening the colonies for desirable properties.

2. A method for formulating an enzyme according to claim 1, wherein screening the colonies for desirable properties comprises:

determining whether the colonies contain active glucose oxidase; and

determining whether the colonies have peroxide resistant properties.

3. A method for formulating an enzyme according to claim 2, wherein screening the colonies for desirable properties further comprises testing glucose oxidase from the colonies for functionality.

4. A method for formulating an enzyme according to claim 2, wherein determining whether the colonies have peroxide resistant properties is only performed if results of determining whether the colonies contain active glucose oxidase are positive.

5. A method for formulating an enzyme according to claim 3, wherein testing glucose oxidase from the colonies for functionality is only performed if results of determining whether the colonies contain active glucose oxidase are positive and if results of determining whether the colonies have peroxide resistant properties are positive.

6. A method for formulating an enzyme according to claim 2, wherein determining whether the colonies have active glucose oxidase comprises employing a substance that changes color in the presence of active glucose oxidase.

7. A method for formulating an enzyme according to claim 6, wherein the substance is leuco-crystal-violet.

8. A method for formulating an enzyme according to claim 2, wherein determining whether the colonies have active glucose oxidase comprises checking for fluorescence.

9. A method for formulating an enzyme according to claim 2, wherein determining whether the colonies have peroxide resistant properties comprises:

incubating the colonies in peroxide; and

determining whether the colonies have active glucose oxidase after incubating the colonies in peroxide.

10. A method for formulating an enzyme according to claim 2, wherein testing glucose oxidase from the colonies for functionality comprises employing glucose oxidase from the colonies in sensors.

11. A method for formulating an enzyme according to claim 10, wherein employing glucose oxidase from the colonies in sensors comprises:

extracting glucose oxidase from the colonies;

immobilizing the glucose oxidase after extracting the glucose oxidase from the colonies;

placing the immobilized glucose oxidase in a sensor; and

testing the sensor.

12. A method for formulating an enzyme according to claim 11, wherein extracting glucose oxidase from the colonies comprises employing an ionic column to extract glucose oxidase from the colonies.

13. A method for formulating an enzyme according to claim 11, wherein extracting glucose oxidase from the colonies comprises:

removing the glucose oxidase from the colonies;

purifying the glucose oxidase; and

characterizing the glucose oxidase.

14. A method for formulating an enzyme according to claim 13, wherein removing the glucose oxidase from the colonies comprises grinding the colonies in a homogenizer into cell components.

15. A method for formulating an enzyme according to claim 14, wherein removing the glucose oxidase from the colonies further comprises fractionating the cell components employing centrifugation and differential solubility after grinding the colonies in a homogenizer.

16. A method for formulating an enzyme according to claim 13, wherein removing the glucose oxidase from the colonies comprises disrupting the colonies into cell components via sonication.

17. A method for formulating an enzyme according to claim 16, wherein removing the glucose oxidase from the colonies further comprises fractionating the cell components employing centrifugation and differential solubility after disrupting the colonies via sonication.

18. A method for formulating an enzyme according to claim 13, wherein purifying the glucose oxidase comprises purifying the glucose oxidase by employing chromatography methods.

19. A method for formulating an enzyme according to claim 1, wherein the glucose oxidase is obtained from an organism and wherein the organism is selected from a group consisting of Aspergillus Niger, Penecillium funiculosum, Saccharomyces cerevisiae, and Escherichia Coli.

20. A method for formulating an enzyme according to claim 1, wherein creating at least one mutated glucose oxidase gene comprises employing polymerase chain reaction techniques to create at least one mutated glucose oxidase gene.

21. A method for formulating an enzyme according to claim 1, wherein creating at least one mutated glucose oxidase gene comprises employing error-prone polymerase chain reaction techniques to create at least one mutated glucose oxidase gene.

22. A method for formulating an enzyme according to claim 1, wherein creating at least one mutated glucose oxidase gene comprises employing gene shuffling techniques to create at least one mutated glucose oxidase gene.

23. A method for formulating an enzyme according to claim 1, wherein the method further comprises creating a next generation of mutated glucose oxidase genes after screening the colonies for desirable properties.

24. A method for formulating an enzyme according to claim 23, wherein creating a next generation of mutated glucose oxidase genes is repeated approximately 2 to 6 times.

25. An enzyme formulated according to the method of claim 1.

26. A method for formulating an enzyme comprising:

obtaining an organism with a glucose oxidase gene;

growing multiple colonies of the organism;

altering the environment of the colonies; and

screening the colonies to identify colonies with active glucose oxidase after altering the environment of the colonies.

27. A method for formulating an enzyme according to claim 26, wherein the organism is selected from a group consisting of Aspergillus Niger, Penecillium funiculosum, Saccharomyces cerevisiae, and Escherichia Coli.

28. A method for formulating an enzyme according to claim 26, wherein altering the environment of the colonies comprises introducing peroxide to the colonies.

29. A method for formulating an enzyme according to claim 26, wherein screening the colonies to identify colonies with active glucose oxidase comprises employing a substance that changes color in the presence of active glucose oxidase.

30. A method for formulating an enzyme according to claim 29, wherein the substance is leuco-crystal-violet.

31. A method for formulating an enzyme according to claim 30, wherein screening the colonies to identify colonies with active glucose oxidase comprises checking for fluorescence.

32. A method for formulating an enzyme according to claim 26, wherein the method further comprises testing the colonies with active glucose oxidase for functionality after screening the colonies to identify colonies with active glucose oxidase.

33. A method for formulating an enzyme according to claim 32, wherein the method further comprises continuing to alter the environments of the colonies until the colonies with active glucose oxidase are of a suitable number to proceed with testing the colonies with active glucose oxidase for functionality.

34. A method for formulating an enzyme according to claim 32, wherein testing the colonies with active glucose oxidase for functionality comprises employing glucose oxidase from the colonies in sensors.

35. A method for formulating an enzyme according to claim 32, wherein testing the colonies with active glucose oxidase for functionality comprises:

extracting glucose oxidase from the colonies;

immobilizing the glucose oxidase after extracting the glucose oxidase from the colonies;

placing the immobilized glucose oxidase in a sensor; and

testing the sensor.

36. A method for formulating an enzyme according to claim 35, wherein extracting glucose oxidase from the colonies comprises employing an ionic column to extract glucose oxidase from the colonies.

37. A method for formulating an enzyme according to claim 35, wherein extracting glucose oxidase from the colonies comprises:

removing the glucose oxidase from the colonies;

purifying the glucose oxidase; and

characterizing the glucose oxidase.

38. A method for formulating an enzyme according to claim 37, wherein removing the glucose oxidase from the colonies comprises grinding the colonies in a homogenizer into cell components.

39. A method for formulating an enzyme according to claim 38, wherein removing the glucose oxidase from the colonies further comprises fractionating the cell components employing centrifugation and differential solubility after grinding the colonies in a homogenizer.

40. A method for formulating an enzyme according to claim 37, wherein removing the glucose oxidase from the colonies comprises disrupting the colonies into cell components via sonication.

41. A method for formulating an enzyme according to claim 40, wherein removing the glucose oxidase from the colonies further comprises fractionating the cell components employing centrifugation and differential solubility after disrupting the colonies via sonication.

42. A method for formulating an enzyme according to claim 37, wherein purifying the glucose oxidase comprises purifying the glucose oxidase by employing chromatography methods.

43. An enzyme formulated according to the method of claim 26.