Claims
- 1. Method for production of a modified ribozyme having a higher biological activity compared to an unmodified ribozyme recognizing the same substrate as said modified ribozyme, said modified and unmodified ribozyme having identical enzymatic portions, comprising the step of forming said modified ribozyme with one or more modified bases in a substrate binding arm of said modified ribozyme.
- 2. The method of claim 1, wherein said modified base has a modification in the chemical structure of a nucleotide base selected from adenosine, guanosine, cytosine or uracil which has an effect on the ability of that base to hydrogen bond with its normal complementary base, either by increasing or decreasing the strength of the hydrogen bonding.
- 3. The method of claim 1, wherein said modified ribozyme has the structure of a hammerhead, hairpin, VS RNA or hepatitis delta virus derived ribozyme.
- 4. The method of claim 3, wherein said hammerhead ribozyme consists of 32 to 40 nucleotide bases.
- 5. The method of claim 1, wherein said modified ribozyme and unmodified ribozyme have different binding free-energies with a target RNA.
- 6. The method of claim 1, wherein said modified base is selected from one shown in FIGS. 6a-d or FIG. 8 or FIG. 14.
- 7. Enzymatic nucleic acid having a non-natural base which enhances the enzymatic activity of said nucleic acid compared to an identical nucleic acid having a naturally-occurring base in place of said non-natural base.
- 8. The enzymatic nucleic acid of claim 7, wherein said non-natural base is selected from one shown in FIGS. 6a-d or FIG. 8 or FIG. 14.
- 9. The enzymatic nucleic acid of claim 7, wherein said nucleic acid has a hammerhead motif.
- 10. An enzymatic nucleic acid having atleast one 6-methyl-uridine substitution.
- 11. A mammalian cell comprising an enzymatic nucleic acid molecule of any one of the claims 1-9.
- 12. Hammerhead ribozyme having a modified base at position 4 or 7.
- 13. The ribozyme of claim 12, wherein said base is 6-methyl uridine.
Parent Case Info
[0001] This application is a continuation-in-part of McSwiggen, “Optimization of Ribozyme Activity”, U.S. Ser. No. 07/963,322, filed Oct. 15, 1992 and Usman et al., entitled “Base-modified enzymatic nucleic acid”, U.S. Ser. No. 08/149,210 (filed Nov. 8, 1993), the whole of both of which, including drawings, is hereby incorporated by reference herein.
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
07963322 |
Oct 1992 |
US |
Child |
09034113 |
Mar 1998 |
US |