Chemical Modification of Hammerhead Ribozymes

Autor: Beigelman, Leonid, McSwiggen, James A., Draper, Kenneth G., Gonzalez, Carolyn, Jensen, Kristi, Karpeisky, Alexander M., Modak, Anil S., Matulic-Adamic, Jasenka, DiRenzo, Anthony B., Haeberli, Peter, Sweedler, David, Tracz, Danuta, Grimm, Susan, Wincott, Francine E., Thackray, Varykina G., Usman, Nassim
Zdroj: Journal of Biological Chemistry; October 1995, Vol. 270 Issue: 43 p25702-25708, 7p
Abstrakt: A systematic study of selectively modified, 36-mer hammerhead ribozymes has resulted in the identification of a generic, catalytically active and nuclease stable ribozyme motif containing 5 ribose residues, 29-30 2′-O-Me nucleotides, 1-2 other 2′-modified nucleotides at positions U4 and U7, and a 3′-3′-linked nucleotide “cap.” Eight 2′-modified uridine residues were introduced at positions U4 and/or U7. From the resulting set of ribozymes, several have almost wild-type catalytic activity and significantly improved stability. Specifically, ribozymes containing 2′-NH2substitutions at U4 and U7, or 2′-C-allyl substitutions at U4, retain most of their catalytic activity when compared to the all-RNA parent. Their serum half-lives were 5-8 h in a variety of biological fluids, including human serum, while the all-RNA parent ribozyme exhibits a stability half-life of only ˜0.1 min. The addition of a 3′-3′-linked nucleotide “cap” (inverted T) did not affect catalysis but increased the serum half-lives of these two ribozymes to >260 h at nanomolar concentrations. This represents an overall increase in stability/activity of 53,000-80,000-fold compared to the all-RNA parent ribozyme.
Databáze: Supplemental Index