Troponin I polypeptide fragments and uses thereof

• US 20020127602A1
• Filed: 08/29/2001
• Published: 09/12/2002
• Est. Priority Date: 10/21/1998
• Status: Active Grant

• Current Assignee: Spectral Diagnostics, Inc.
• Original Assignee: Spectral Diagnostics, Inc.
• Inventors: Shi, Qinwei, Ling, Mingfu, Liu, Shigui
• Granted Patent: US 7,479,278 B2
• Time in Patent Office: Days
• US Class Current: 435/7.1
• CPC Class Codes: A61K 38/00 Medicinal preparations containing peptides peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00
• CPC Class Codes: C07K 14/4716 Muscle proteins, e.g. myosin, actin

Abstract

Polypeptides corresponding to stable, circulating degradation products of troponin I (TnI) are described. The fragments comprise a sequence of the N-terminus of native cardiac TnI with 95-115 amino acid and additionally include fragments lacking about the 20-30 N-terminal amino acids. Utilities of these fragments and antibodies thereto include sensitive detection of myocardial infarction and purification of antibodies sensitive to the detection of troponin I degradation products.

Claims

1. An isolated polypeptide corresponding to an N-terminal fragment of human cardiac troponin I consisting of about 95 to about 115 amino acids.

2. The troponin I fragment of claim 1 which has an intact, native cardiac troponin I N-terminus.

3. The troponin I fragment of claim 2 represented by SEQ ID NO:

2.

9. The troponin I fragment of claim 1 comprising a sequence from about amino acid 20 to 30, to about amino acid 95 to 115.

10. A method of preparing antibodies that recognize a stable, in-vivo-occurring fragment of troponin I by using a troponin I fragment of claim 1 as an immunogen.

11. A method of purifying anti-troponin I antibodies that recognized a stable, in-vivo-occurring fragment of troponin I by using the troponin I fragment of claim 1 as a reagent for affinity purification.

12. Calibrators and controls for a troponin I immunoassay comprising a polypeptide of claim 1.

13. The calibrators and controls of claim 12 as shown in SEQ ID NO:

2.

14. A method for the immunodetection of human cardiac troponin I in a bodily fluid utilizing an antibody which is raised against the polypeptide of claim 1.

15. A kit for the immunodetection of human cardiac troponin I in a sample of bodily fluid comprising:

(a) an antibody which is raised against the polypeptide of claim 1;

(b) means for determining the extent of interaction of said antibody with troponin I in said sample.

4. The polynucleotide sequence of a troponin I fragment as set forth in SEQ ID NO:

2.

5. A replicable cloning or expression vehicle comprising a polynucleotide sequence coding for the polypeptide set forth in SEQ ID NO:

2.

6. A host cell transformed with the vehicle of claim 5.

7. The host cell of claim 6 which is an E. coli host cell.

8. The E. coli host cell of claim 7 having the ATCC number 98824.