Methods of producing nucleic acid ligands

• US 5,595,877 A
• Filed: 05/16/1995
• Issued: 01/21/1997
• Est. Priority Date: 06/11/1990
• Status: Expired due to Term

• Current Assignee: Gilead Sciences Inc.
• Original Assignee: NeXstar Pharmaceuticals, Inc. (Gilead Sciences Inc.)
• Inventors: Gold, Larry, Tuerk, Craig
• Primary Examiner(s): Zitomer, Stephanie W.
• Application Number:
  US08/442,062
• Time in Patent Office: 616 Days
• Field of Search: 435/6, 435/91.2
• US Class Current: 435/6.11
• 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: A61K 47/547 Chelates, e.g. Gd-DOTA or Zinc-amino acid chelates; Chelate-forming compounds, e.g. DOTA or ethylenediamine being covalently linked or complexed to the pharmacologically- or therapeutically-active agent
• CPC Class Codes: A61K 47/549 Sugars, nucleosides, nucleotides or nucleic acids
• CPC Class Codes: B82Y 5/00 Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery
• CPC Class Codes: C07H 21/00 Compounds containing two or more mononucleotide units having separate phosphate or polyphosphate groups linked by saccharide radicals of nucleoside groups, e.g. nucleic acids
• CPC Class Codes: C07K 14/001 by chemical synthesis
• CPC Class Codes: C07K 14/005 from viruses
• CPC Class Codes: C07K 14/72 for hormones for neuromediators C07K14/70571
• CPC Class Codes: C07K 7/22 Tachykinins, e.g. Eledoisins , Substance P; Related peptides
• CPC Class Codes: C12N 15/1048 SELEX
• CPC Class Codes: C12N 15/1058 Directional evolution of libraries, e.g. evolution of libraries is achieved by mutagenesis and screening or selection of mixed population of organisms
• CPC Class Codes: C12N 15/115 Aptamers, i.e. nucleic acids binding a target molecule specifically and with high affinity without hybridising therewith ; Nucleic acids binding to non-nucleic acids, e.g. aptamers
• CPC Class Codes: C12N 2310/13 Decoys
• CPC Class Codes: C12N 2310/322 2'-R Modification
• CPC Class Codes: C12N 2310/53 partially self-complementary or closed
• CPC Class Codes: C12N 2740/16222 New viral proteins or individual genes, new structural or functional aspects of known viral proteins or genes
• CPC Class Codes: C12N 9/1276 RNA-directed DNA polymerase (2.7.7.49), i.e. reverse transcriptase or telomerase
• CPC Class Codes: C12Q 1/37 involving peptidase or proteinase
• CPC Class Codes: C12Q 1/6811 Selection methods for production or design of target specific oligonucleotides or binding molecules
• CPC Class Codes: C12Q 1/703 Viruses associated with AIDS
• CPC Class Codes: C12Q 2525/101 : incorporating non-naturally occurring nucleotides, e.g. inosine
• CPC Class Codes: C12Q 2525/301 : Hairpin oligonucleotides
• CPC Class Codes: C12Q 2541/101 : Selex
• CPC Class Codes: C40B 40/00 : Libraries per se, e.g. arrays, mixtures
• CPC Class Codes: F02B 2075/027 : four
• CPC Class Codes: G01N 2333/16 : HIV-1, HIV-2
• CPC Class Codes: G01N 2333/163 : Regulatory proteins, e.g. tat, nef, rev, vif, vpu, vpr, vpt, vpx
• CPC Class Codes: G01N 2333/503 : basic FGF [bFGF]
• CPC Class Codes: G01N 2333/575 : Hormones
• CPC Class Codes: G01N 2333/62 : Insulins
• CPC Class Codes: G01N 2333/8125 : Alpha-1-antitrypsin
• CPC Class Codes: G01N 2333/918 : Carboxylic ester hydrolases (3.1.1)
• CPC Class Codes: G01N 2333/96433 : Serine endopeptidases (3.4.21)
• CPC Class Codes: G01N 2333/96436 : Granzymes
• CPC Class Codes: G01N 2333/96455 : Kallikrein (3.4.21.34; 3.4.21.35)
• CPC Class Codes: G01N 2333/96486 : Metalloendopeptidases (3.4.24)
• CPC Class Codes: G01N 2333/966 : Elastase
• CPC Class Codes: G01N 2333/9726 : Tissue plasminogen activator
• CPC Class Codes: G01N 2333/974 : Thrombin
• CPC Class Codes: G01N 2333/976 : Trypsin; Chymotrypsin
• CPC Class Codes: G01N 33/531 : Production of immunochemical test materials
• CPC Class Codes: G01N 33/532 : Production of labelled immunochemicals
• CPC Class Codes: G01N 33/535 : with enzyme label or co-enzymes, co-factors, enzyme inhibitors or enzyme substrates
• CPC Class Codes: G01N 33/56988 : HIV or HTLV
• 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 33/76 : Human chorionic gonadotropin including luteinising hormone, follicle stimulating hormone, thyroid stimulating hormone or their receptors

Abstract

The present invention includes methods for the identification and production of improved nucleic acid ligands based on the SELEX process. Also included are nucleic acid ligands to the HIV-RT protein identified according to the methods described therein.

Claims

1. A method for preparing an improved nucleic acid ligand;

wherein said improvement is produced by modifying a nucleic acid ligand to have at least one of the following improved properties;

decreased size, enhanced stability, or enhanced binding affinity, said nucleic acid ligand being a ligand of a given target comprising;

a) contacting a candidate mixture of of nucleic acids with the target, wherein nucleic acids having an increased affinity to the target relative to the candidate mixture may be partitioned from the remainder of the candidate mixture;

b) partitioning the increased affinity nucleic acids from the remainder of the candidate mixture;

c) amplifying the increased affinity nucleic acids to yield a ligand-enriched mixture of nucleic acids;

d) repeating steps a)-c), as necessary, to identify a nucleic acid ligand;

e) modifying the nucleic acid ligand of step d), wherein said modifying comprises adding, deleting, or substituting nucleotide said residues, wherein said residues may may be chemically modified, and/or chemically modifying said nucleic acid ligand; and

f) determining whether the modified nucleic acid ligand of step e) has at least one of said improved properties relative to the nucleic acid ligand of step d) whereby said improved nucleic acid ligand may be prepared.

2. The method of claim 1 wherein step c) comprises preparing an improved nucleic acid ligand that is identical to the nucleic acid ligand of step d) except for a single residue substitution.

4. The method of claim 1 wherein step e) comprises preparing an improved nucleic acid ligand by chemically modifying the nucleic acid ligand of step d).

5. The method of claim 1 wherein in step e) the nucleic acid ligand of step d) is modified while in contact with the target.

11. The method of claim 1 wherein step e) comprises substitution of chemically modified nucleotides in the nucleic acid ligand of step d).

12. The method of claim 11 wherein said chemically modified nucleotides are selected from the group consisting of 5-position modified pyrimidines, 8-position modified purines, 2'"'"'-modified nucleotides or combinations thereof.

13. The method of claim 11 wherein step e) comprises the substitution of a 2'"'"'-modified nucleotide for its respective 2'"'"'-OH nucleotide in the nucleic acid ligand of step d).

14. The method of claim 13 wherein said 2'"'"'-modified nucleotide is selected from the group consisting of 2'"'"'-F nucleotides, 2'"'"'-NH₂ nuclcotides, and 2'"'"'-O-Methyl nucleotides.

15. The method of claim 1 wherein step e) comprises the addition of nucleotides to the 5'"'"' end of the nucleic acid ligand of step d), the 3'"'"' end of the nucleic acid ligand of step d), or both.

16. The method of claim 1 wherein the improved property determined in step f) is enhanced binding affinity for the target.

17. The method of claim 1 wherein the improved property determined in step f) is enhanced stability.

18. The method of claim 17 wherein said improved property of enhanced stability is determined by resistance to degradation in situ.

19. The method of claim 17 wherein said improved property of enhanced stability is determined by decreased clearance in situ.

20. The method of claim 17 wherein said improved property of enhanced stability is determined by reduced nucleic acid content relative to the unimproved nucleic acid ligand.

21. The method of claim 1 wherein the improved property determined in step f) is decreased size.

22. The method of claim 21 wherein said improved nucleic acid ligand having said decreased size property retains binding affinity for the target.

23. The method of claim 21 wherein said improved nucleic acid ligand having said decreased size property has enhanced binding affinity for the target.

3. The method of clam 1 wherein step e) comprises preparing an improved nucleic acid ligand and that is identical to the nucleic acid ligand of step d) except for the absence of one or more terminal residues.

6. A method for preparing an improved nucleic acid ligand, wherein said improvement is produced by modifying a nucleic acid ligand to have at least one of the following improved properties:

decreased size, enhanced stability, or enhanced binding affinity, said nucleic acid ligand being a ligand of a given target comprising;

a) contacting a candidate mixture with the target, wherein nucleic acids having an increased affinity to the target relative to the candidate mixture may be partitioned from the remainder of the candidate mixture;

b) partitioning the increased affinity nucleic acids from the remainder of the candidate mixture;

c) amplifying the increased affinity nucleic acids to yield a ligand-enriched mixture of nucleic acids;

d) repeating steps a)-c) as necessary to identify said nucleic acid ligand of a given target;

e) determining the three-dimensional structure of said nucleic acid ligand;

f) modifying the nucleic acid ligand of step d) based on the determined three-dimensional structure of the nucleic acid ligand, wherein said modifying comprises adding, deleting, or substituting nucleotide residues, wherein said residues may be chemically modified, and/or chemically modifying said nucleic acid ligand; and

g) determining whether the modified nucleic acid ligand of step f) has improved properties relative to the nucleic acid of step d), whereby said improved nucleic acid ligand may be prepared.

7. The method of claim 6 wherein in step e) the three-dimensional structure of a nucleic acid ligand is determined by

i) chemically modifying denatured and nondenatured nucleic acid ligand;

and

ii) determining which nucleotide residues are modified in the denatured nucleic acid ligand that are not modified in the nondenatured nucleic acid ligand.

8. The method of claim 6 wherein in each of steps d) and e), said nucleic acid ligand comprises a plurality of nucleic acid ligands, and in step e) the three-dimensional structure of the nucleic acid ligands is determined by covariance analysis on said plurality of nucleic acid ligands of step d).

9. A method for designing an improved nucleic acid ligand to a given target from a plurality of nucleic acid ligands to said target, wherein said improved nucleic acid ligand has at least one of the following improved properties:

decreased size, enhanced stability, or enhanced binding affinity, and wherein said designing is accomplished by the method comprising;

a) determining the three dimensional structure of said nucleic acid ligands;

b) determining the nucleic acid residues of said nucleic acid ligands that bind to said target; and

c) designing said improved nucleic acid ligand to said target wherein said improved properties are obtained by modifying said nucleic acid ligand by adding, deleting, or substituting nucleotide residues based on said determinations made in steps a) and b) and wherein said added or substituted nucleotide residues may be chemically modified.

10. A method for designing an improved nucleic acid ligand having at least one of the following improved properties:

decreased size, enhanced stability, or enhanced binding affinity, said nucleic acid ligand being a ligand of a given target comprising;

(a) contacting a candidate mixture of nucleic acids with a target, wherein nucleic acids having an increased affinity to the target relative to the candidate mixture may be partitioned from the remainder of the candidate mixture;

(b) partitioning the increased affinity nucleic acids from the remainder of the candidate mixture;

(c) amplifying the increased affinity nucleic acids to yield a ligand-enriched mixture of nucleic acids;

(d) repeating steps (a)-(c), as necessary, to identify a nucleic acid ligand of a given target;

(e) determining the three-dimensional structure of said nucleic acid ligand;

(f) determining the nucleic acid residues of the nucleic acid ligand that bind to said target; and

(g) designing said improved ligand to said target wherein said improved properties are obtained by modifying said nucleic acid ligand by adding, deleting, or substituting nucleotide residues based on said determinations made in steps e) and f) and wherein said added or substituted nucleotide residues may be chemically modified.

24. A method for designing an improved nucleic acid ligand having at least one of the following improved properties;

decreased size, enhanced stability, or enhanced binding affinity, from a plurality of unimproved nucleic acid ligands, wherein said designing is accomplished by the method comprising;

a) contacting a candidate mixture with a target, wherein nucleic acids having an increased affinity to the target relative to the candidate mixture may be partitioned from the remainder of the candidate mixture;

b) partitioning the increased affinity nucleic acids from the remainder of the candidate mixture;

c) amplifying the increased affinity nucleic acids to yield a ligand-enriched mixture of nucleic acids;

d) repeating steps a)-c) as necessary to identify said plurality of unimproved nucleic acid ligands;

e) determining the consensus primary structure of said nucleic acid ligands;

f) designing an improved nucleic acid ligand by adding, deleting, or substituting nucleotide residues based on said consensus primary structure, wherein said residues may be chemically modified, based on the determined consensus primary structure of the nucleic acid ligands of step d); and

g) determining whether the improved nucleic acid ligand of step f) has improved properties relative to the nucleic acid ligands of step d), whereby said improved nucleic acid ligand may be designed.

25. The method of claim 24 said improved nucleic acid ligand of step f) is designed by deleting a portion of the nucleotides that are not part of the consensus primary structure.

26. A method for designing an improved nucleic acid ligand having at least one of the following improved properties:

decreased size, enhanced stability, or enhanced binding affinity, from a plurality of unimproved nucleic acid ligands, wherein said designing is determined by the method comprising;

a) contacting a candidate mixture with a target, wherein nucleic acids having an increased affinity to the target relative to the candidate mixture may be partitioned from the remainder of the candidate mixture;

b) partitioning the increased affinity nucleic acids from the remainder of the candidate mixture;

c) amplifying the increased affinity nucleic acids to yield a ligand-enriched mixture of nucleic acids;

d) repeating steps a)-c) as necessary to identify said plurality of unimproved nucleic acid ligands;

e) determining the consensus secondary structure of said nucleic acid ligand;

f) designing an improved nucleic acid ligand by adding, deleting or substituting nucleotide residues based on said consensus secondary structure, wherein said residues may be chemically modified based on the determined consensus secondary structure of the nucleic acid ligands of step d); and

g) determining whether the improved nucleic acid ligand of step f) has improved properties relative to the nucleic acid ligands of step d), whereby said improved nucleic acid ligand may be designed.

27. The method of claim 26 wherein said improved nucleic acid ligand of step f) is designed by deleting a portion of the nucleotides that are not part of the consensus secondary structure.

28. The method of claim 26 said nucleic acid ligand in step e) comprises a plurality nucleic acid ligands and the consensus secondary structure is determined by covariance analysis.