Ratiometric determination of glycated protein

• US 7,195,923 B2
• Filed: 01/31/2002
• Issued: 03/27/2007
• Est. Priority Date: 01/31/2001
• Status: Expired due to Term

• Current Assignee: Biohermes
• Original Assignee: Scripps Laboratories, Inc. (Scripps Health)
• Inventors: McCroskey, Ralph P., Melton, Cameron E.
• Primary Examiner(s): Le; Long V.
• Assistant Examiner(s): Venci; David J.
• Application Number:
  US10/061,438
• Publication Number:
  US 20030068830A1
• Time in Patent Office: 1,881 Days
• Field of Search: 435/7.4, 435/7.6, 435/7.9, 435/7.92, 435/7.7, 435/7.8, 435/14, 435/179, 435/180, 435/181, 435/188, 435/287.7, 435/287.9, 435/288.3, 435/288.7, 435/803, 435/805, 435/815, 435/817, 435/962, 435/967, 435/970, 435/973, 436/501, 436/67, 436161-162, 436/164, 436/14, 436/15, 436/16, 436/18, 436/46, 436/129, 436/131, 436/151, 436/66, 436/87, 436/88, 436/166, 436/169, 436/174, 436/175, 436/177, 436/178, 436/805, 436/810, 436/815, 436/825, 530/413, 530/369, 530/385, 530/395, 530/403, 530/415, 530/416, 530/417, 422/70, 422/56, 422/57, 210/663, 210/668, 210/660, 210/500.29, 210/500.34, 210/500.35, 210/500.38, 210/500.42, 600/477, 356/39, 356/40, 356/433, 521/32, 521/901, 523/344, 524/195, 524/183, 524/404, 524/405, 524/701, 527/301, 527/311, 528/69, 560/334, 427/308, 427/324, 427/339, 427/415, 427/439
• US Class Current: 436/87
• CPC Class Codes: G01N 2400/00 Assays, e.g. immunoassays or enzyme assays, involving carbohydrates
• CPC Class Codes: G01N 33/54386 Analytical elements
• CPC Class Codes: G01N 33/68 involving proteins, peptides or amino acids involving lipoproteins G01N33/92
• CPC Class Codes: G01N 33/6842 Proteomic analysis of subsets of protein mixtures with reduced complexity, e.g. membrane proteins, phosphoproteins, organelle proteins
• CPC Class Codes: G01N 33/723 Glycosylated haemoglobin
• CPC Class Codes: Y10S 435/803 Physical recovery methods, e.g. chromatography, grinding
• CPC Class Codes: Y10S 435/805 Test papers
• CPC Class Codes: Y10S 435/815 by sorption
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode
• CPC Class Codes: Y10S 435/962 Prevention or removal of interfering materials or reactants or other treatment to enhance results, e.g. determining or preventing nonspecific binding
• CPC Class Codes: Y10S 435/967 Standards, controls, materials, e.g. validation studies, buffer systems
• CPC Class Codes: Y10S 435/97 Test strip or test slide
• CPC Class Codes: Y10S 435/973 Simultaneous determination of more than one analyte
• CPC Class Codes: Y10S 436/805 Optical property
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick
• CPC Class Codes: Y10S 436/815 Test for named compound or class of compounds
• CPC Class Codes: Y10S 436/825 Pretreatment for removal of interfering factors from sample
• CPC Class Codes: Y10T 436/104998 Glucose, ketone, nitrate standard or control
• CPC Class Codes: Y10T 436/105831 Protein or peptide standard or control [e.g., hemoglobin, etc.]
• CPC Class Codes: Y10T 436/106664 Blood serum or blood plasma standard or control
• CPC Class Codes: Y10T 436/108331 : Preservative, buffer, anticoagulant or diluent
• CPC Class Codes: Y10T 436/112499 : with sample on test slide
• CPC Class Codes: Y10T 436/201666 : Carboxylic acid
• CPC Class Codes: Y10T 436/203332 : Hydroxyl containing
• CPC Class Codes: Y10T 436/25 : including sample preparation
• CPC Class Codes: Y10T 436/25125 : Digestion or removing interfering materials
• CPC Class Codes: Y10T 436/25375 : Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]
• CPC Class Codes: Y10T 436/255 : including use of a solid sorbent, semipermeable membrane, or liquid extraction

Abstract

The present invention provides methods for determining a ratio of an amount of a glycated form of a protein to a total amount of the protein in a sample containing the glycated protein, the glycosylated protein, or the glycoprotein. The method incorporates lateral flow test strip or vertical flow test strip devices having negatively charged carboxyl or carboxylate groups and hydroxyboryl groups immobilized and interspersed on a solid support matrix. The solid support matrix may include derivatives of cellulose (e.g., carboxy cellulose) derivatized with carboxylic acid (e.g., carboxylate, carboxyl) groups and hydroxyboryl compounds including phenylboronic acid (e.g., phenylborate), aminophenylboronic acid, boric acid (e.g., borate), or other boronic acid (e.g., boronate) compounds. The present invention is usefi.il for monitoring glycation or glycosylation of hemoglobin or albumin for monitoring glycemic control (e.g., glycemia in diabetes).

Claims

1. A method for determining a ratio of an amount of a glycated form of a protein to a total amount of the protein in a sample containing both glycated and nonglycated forms of the protein, comprising:

providing a solid support having negatively charged carboxyl groups immobilized thereon, which groups are capable of binding both the glycated and the nonglycated forms of the protein at a first pH, said support also having hydroxyboryl groups immobilized thereon, interspersed with the negatively charged carboxyl groups, which hydroxyboryl groups are capable of binding the glycated form of the protein at a second pH;

adding the sample to the solid support at the first pH, thereby binding both the glycated and the nonglycated forms of the protein to the negatively charged carboxyl groups on the solid support, and then performing a first measurement indicative of the total amount of the glycated and the nonglycated forms of the protein bound to the solid support;

changing the pH on the support to the second pH, thereby removing both the nonglycated form of the protein and the glycated form of the protein from the negatively charged carboxyl groups, after which removal the glycated form of the protein immediately binds to the hydroxyboryl groups on the support independent of incubation time, and then performing a second measurement indicative of the amount of the glycated form of the protein bound to the solid support; and

determining the ratio of the amount of the glycated form of the protein to the total amount of the glycated and the nonglycated forms of the protein in the sample from the first and second measurements.

2. The method of claim 1, wherein the first pH is achieved by applying a buffer of about pH 5.0 to 7.0.

3. The method of claim 1, wherein the second pH is achieved by applying a buffer of about pH 8.0 to 10.0.

4. The method of claim 1, wherein the glycated protein is hemoglobin.

5. The method of claim 1, wherein the glycated protein is albumin.

6. The method of claim 1, wherein the sample comprises blood.

7. The method of claim 1, wherein the sample comprises serum.

8. The method of claim 1, wherein the sample comprises plasma.

9. The method of claim 1, wherein the first and second measurements measure an optical property of the protein.

10. The method of claim 1, wherein the first and second measurements are optical readings at a predetermined wavelength.

11. The method of claim 1, wherein the first and second measurements measure a protein label.

12. The method of claim 1, wherein the hydroxyboryl group is of the type

13. The method of claim 1, wherein the solid support is selected from the group consisting of cellulose, nitrocellulose, cellulose acetate, polyacrylamide, agarose polyacrylamide copolymer, agarose, starch, nylon, nylon polyesters, dextran, cross-linked dextran, dextran acrylamide copolymer, cross-linked hydroxyethylmethacrylate, substituted cross-linked polystyrenes, polyvinylalcohol, wool, metal oxides, porous ceramics coated with hydrophilic organic polymers and glass.

14. A method for determining a ratio of an amount of glycated albumin to a total amount of glycated and nonglycated albumin in a sample containing both glycated and nonglycated albumin, comprising:

providing a strip-type device comprising;

(1) a solid support matrix having a measurement area; and

(2) negatively charged carboxyl groups and dihydroxyboryl groups immobilized and interspersed on the solid support matrix, said negatively charged carboxyl groups are capable of binding both glycated and nonglycated albumin at a first pH between about 5.0 and about 7.0, and said dihydroxyboryl groups are capable of binding glycated albumin at a second pH between about 8.0 and about 10.0;

adding the sample to the solid support matrix at the first pH, thereby binding both glycated and nonglycated albumin to the negatively charged carboxyl groups on the solid support matrix, and then performing a first optical measurement on the measurement area indicative of the total amount of glycated and nonglycated albumin bound to the solid support matrix;

changing the pH on the solid support matrix to the second pH, thereby removing both the nonglycated albumin and the glycated albumin from the negatively charged carboxyl groups, after which removal the glycated albumin immediately binds to the dihydroxyboryl groups on the solid support matrix independent of incubation time, and then performing a second optical measurement on the measurement area indicative of the amount of glycated albumin bound to the solid support matrix; and

determining the ratio of the amount of glycated albumin to the total amount of glycated and nonglycated albumin in the sample from the first and second optical measurements.

15. The method of claim 14, wherein said dihydroxyboryl groups have the formula:

16. The method of claim 14, wherein the solid support matrix is selected from the group consisting of cellulose, nitrocellulose, cellulose acetate, polyacrylamide, agarose polyacrylamide copolymer, agarose, starch, nylon, nylon polyesters, dextran, cross-linked dextran, dextran acrylamide copolymer, cross-linked hydroxyethylmethacrylate, substituted cross-linked polystyrenes, polyvinylalcohol, wool, metal oxides, porous ceramics coated with hydrophilic organic polymers and glass.

17. The method of claim 16, wherein said solid support matrix is carboxy cellulose.

18. The method of claim 14, wherein said first pH is achieved with a buffer selected from the group consisting of MES, MOPS and HEPES.

19. The method of claim 14, wherein said second pH is achieved with a buffer selected from the group consisting of ammonium acetate or taurine.

20. The method of claim 14, wherein the sample comprises blood, plasma or serum.

21. A method for determining a ratio of an amount of glycated hemoglobin to a total amount of glycated and nonglycated hemoglobin in a sample containing both glycated and nonglycated hemoglobin, comprising:

providing a strip-type device comprising;

(1) a solid support matrix having a measurement area; and

(2) negatively charged carboxyl groups and dihydroxyboryl groups immobilized and interspersed on the solid support matrix, said negatively charged carboxyl groups are capable of binding both glycated and nonglycated hemoglobin at a first pH between about 5.0 and about 7.0, and said dihydroxyboryl groups are capable of binding glycated hemoglobin at a second pH between about 8.0 and about 10.0;

adding the sample to the solid support matrix at the first pH, thereby binding both glycated and nonglycated hemoglobin to the negatively charged carboxyl groups on the solid support matrix, and then performing a first optical measurement on the measurement area indicative of the total amount of glycated and nonglycated and nonglycated hemoglobin bound to the solid support matrix;

changing the pH on the solid support matrix to the second pH, thereby removing both the nonglycated hemoglobin and the glycated hemoglobin from the negatively charged carboxyl groups, after which removal the glycated hemoglobin immediately binds to the dihydroxyboryl groups on the solid support matrix independent of incubation time, and then performing a second optical measurement on the measurement area indicative of the amount of glycated homoglobin bound to the solid support matrix; and

determining the ratio of the amount of glycated hemoglobin to the total amount of glycated and nonglycated hemoglobin in the sample from the first and second optical measurements.

22. The method of claim 21, wherein said dihydroxyboryl groups have the formula:

23. The method of claim 21, wherein the solid support matrix is selected from the group consisting of cellulose, nitrocellulose, cellulose acetate, polyacrylamide, agarose polyacrylamide copolymer, agarose, starch, nylon, nylon polyesters, dextran, cross-linked dextran, dextran acrylamide copolymer, cross-linked hydroxyethylmethacrylate, substituted cross-linked polystyrenes, polyvinylalcohol, wool, metal oxides, porous ceramics coated with hydrophilic organic polymers and glass.

24. The method of claim 21, wherein said solid support matrix is carboxy cellulose.

25. The method of claim 21, wherein said first pH is achieved with a buffer selected from the group consisting of MES, MOPS and HEPES.

26. The method of claim 21, wherein said second pH is achieved with a buffer selected from the group consisting of ammonium acetate or taurine.

27. The method of claim 21, wherein the sample comprises blood, plasma or serum.