Biomarkers
The invention provides binding agents and assays for insulin signal peptide. The agents and assays are useful in methods for predicting, diagnosing, assessing or monitoring acute cardiac disorders, glucose handling disorders and diabetes in a subject. Also provided are nucleotides, polypeptides, and kits useful in the methods of the invention.
1. An isolated monoclonal antibody, or antigen-binding fragment thereof, that selectively binds to insulin signal peptide fragment (1-9) (SEQ ID NO:16) in a biological sample, wherein the monoclonal antibody, or antigen binding fragment thereof, is labeled with a detectable marker or bound to a solid substrate.
2. The monoclonal antibody, or antigen-binding fragment thereof, according to claim 1 , which is bound to a solid substrate.
3. The monoclonal antibody, or antigen-binding fragment thereof, according to claim 1 , which is labeled with a detectable marker.
4. An immunoassay device comprising:
the antibody, or antigen-binding fragment thereof, according to claim 1 ; and
a solid substrate,
wherein the antibody, or antigen-binding fragment thereof, is bound to the solid substrate and is capable of binding an insulin signal peptide fragment when placed in contact with a sample comprising an insulin signal peptide fragment in order to measure the level of said insulin signal peptide fragment in said sample.
5. The immunoassay device according to claim 4 , wherein the device is configured to perform an immunoassay selected from the group consisting of ELISAs, fluoroimmunoassays, immunofluorometric assays, and immunoradiometric assays.
6. The immunoassay device according to claim 4 , wherein the monoclonal antibody, or antigen-binding fragment thereof, is labeled with a detectable marker.
7. The immunoassay device according to claim 4 , wherein the immunoassay is a sandwich immunoassay.
8. The immunoassay device according to claim 4 , wherein the immunoassay is an radioimmunoassay (RIA).
9. The immunoassay device according to claim 4 , wherein the immunoassay device comprises a disposable testing cartridge.
10. A kit comprising the monoclonal antibody, or antigen-binding fragment thereof, according to claim 1 .
11. A kit according to claim 10 , wherein the kit is calibrated to measure insulin signal peptide fragment levels ranging from 0.1 to 500 pmol/L, 1 to 300 pmol/L, or 10 to 250pmol/L.
12. The kit according to claim 10 , wherein the monoclonal antibody, or antigen-binding fragment thereof, is bound to a solid substrate.
13. The kit according to claim 10 , wherein the kit comprises
instructions for predicting, diagnosing, or monitoring said acute cardiac disorder a biological event or disorder in a subject from the insulin signal peptide fragment level in a biological sample from the subject as measured by an assay selected from the group consisting of an enzyme-linked immunosorbent assay, a radioimmunoassay, a fluoroimmunoassay, and an immunofluorometric assay.
14. The kit according to claim 10 wherein the kit is adapted for use in an enzyme-linked immunosorbent assay.
15. A kit according to claim 10 wherein the monoclonal antibody, or antigen-binding fragment thereof, is directly or indirectly adsorbed or bound to a solid substrate.
16. A kit according to claim 15 wherein the solid substrate is a plate, bead, or tube.
17. A kit according to claim 10 that further comprises a secondary antibody or antigen-binding antibody fragment that also binds the insulin signal peptide fragment, wherein the secondary antibody or antigen-binding antibody fragment binds a site on the insulin signal peptide fragment that is different from the binding site bound by the monoclonal antibody or antigen-binding fragment thereof.
18. A kit according to claim 17 wherein the secondary antibody or antigen-binding antibody fragment is labeled.
19. A kit according to claim 17 that further comprises a third antibody or antigen-binding antibody fragment, which third antibody or antigen-binding antibody fragment is labeled with a detectable label and binds to the secondary antibody.
20. A kit comprising:
(a) the monoclonal antibody, or antigen-binding fragment thereof, according to claim 1 in an enzyme-linked immunosorbent assay format; and
(b) and instructions for predicting, diagnosing, or monitoring an acute cardiac disorder, a biological event or disorder in a subject from the insulin signal peptide fragment level in a biological sample from the subject.
21. A kit according to claim 20 wherein the monoclonal antibody, or antigen-binding fragment thereof, is directly or indirectly adsorbed or bound to a solid substrate.
22. A kit according to claim 21 wherein the solid substrate is a plate, bead, or tube.
23. An assay system comprising:
a mass spectroscopy device; and
a probe, wherein the probe comprises a monoclonal antibody, or antigen-binding fragment thereof, that is bound to a solid substrate and that selectively binds to insulin signal peptide fragment (1-9) (SEQ ID NO:16) in a biological sample.
24. The assay system according to claim 23 wherein the mass spectroscopy device is selected from the group consisting of devices capable of SELDI, ESI, MALDI, and FTICR mass spectroscopy.
25. The assay system according to claim 24 wherein the probe comprises a surface-enhanced laser desorption ionization (SELDI) probe.