The proposed research aims to apply the DNA cleaving RNA enzymes and RNA cleaving DNA enzymes to HIV-1 and FIV targets, culminating in an assessment of antiviral efficacy in FIV infected cells. A program of medicinal biochemistry will be carried out, addressing issues of compound potency, specificity, stability, delivery, and formulation. The RNA cleaving DNA enzymes will receive the greatest attention. These compounds are comprised of only 30 deoxynucleotides, yet have a catalytic efficiency exceeding that of any other known nucleic acid enzyme. DNA enzymes will be designed to cleave target sites within FIV RNA, then tested in feline lymphocytic cells that have been infected with FIV. DNA enzymes also will be designed to cleave mRNAs encoding various HIV-1 co-receptor proteins, These molecule will be made available to the AIDS research community for use as a chemical """"""""knock out"""""""" agents in studying the role that beta chemokine receptors play in HIV-1 pathogenesis. Finally, in vitro evolution methods will be used to develop DNA enzymes with glycosidase activity. Such molecules might be used to cleave cell-surface glycoproteins , such as the HIV-1 gp 120 envelope glycoproteins.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
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AIDS and Related Research Study Section 4 (ARRD)
Program Officer
Sarver, Nava
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Scripps Research Institute
La Jolla
United States
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Joyce, G F (2001) RNA cleavage by the 10-23 DNA enzyme. Methods Enzymol 341:503-17
Sheppard, T L; Ordoukhanian, P; Joyce, G F (2000) A DNA enzyme with N-glycosylase activity. Proc Natl Acad Sci U S A 97:7802-7
Santoro, S W; Joyce, G F (1998) Mechanism and utility of an RNA-cleaving DNA enzyme. Biochemistry 37:13330-42
Raillard, S A; Joyce, G F (1996) Targeting sites within HIV-1 cDNA with a DNA-cleaving ribozyme. Biochemistry 35:11693-701
Tsang, J; Joyce, G F (1996) Specialization of the DNA-cleaving activity of a group I ribozyme through in vitro evolution. J Mol Biol 262:31-42
Tsang, J; Joyce, G F (1996) In vitro evolution of randomized ribozymes. Methods Enzymol 267:410-26
Breaker, R R; Joyce, G F (1994) Emergence of a replicating species from an in vitro RNA evolution reaction. Proc Natl Acad Sci U S A 91:6093-7
Tsang, J; Joyce, G F (1994) Evolutionary optimization of the catalytic properties of a DNA-cleaving ribozyme. Biochemistry 33:5966-73
Beaudry, A A; Joyce, G F (1992) Directed evolution of an RNA enzyme. Science 257:635-41
Cadwell, R C; Joyce, G F (1992) Randomization of genes by PCR mutagenesis. PCR Methods Appl 2:28-33