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Template-directed synthesis of oligoguanylic acids - Metal ion catalysisThe effects of Zn(2+), Pb(2+) and other metal ions on the efficiency and stereo-selectivity of the template-directed oligomerization of guanosine 5'-phosphorimidazolide are investigated. Reactions were run in the presence of a polyC template in a 2,6-lutidine buffer, and products analyzed by high-performance liquid chromatography on an RPC-5 column. The presence of the Pb(2+) ion is found to lead to the formation of 2'-5' linked oligomers up to the 40-mer, while Zn(2+) favors the formation of predominantly 3'-5' linked oligomers up to the 35-mer. When amounts of uracil, cytidine or adenosine 5'-phosphorimidazole equal to those of the guanosine derivative are included in the reaction mixture, the incorrect base is incorporated into the oligomer about 10% of the time with a Pb(2+) catalyst, but less than 0.5% of the time with Zn(2+). The Sn(2+), Sb(3+) and Bi(3+) ions are also found to promote the formation of 2'-5' oligomers, although not as effectively as Pb(2+), while no metal ions other than Zn(2+) promote the formation of the 3'-5' oligomers. The results may be important for the understanding of the evolution of nucleic acid replication in the absence of enzymes.
Document ID
19820037397
Document Type
Conference Proceedings
Authors
Bridson, P. K. (Salk Inst. for Biological Studies San Diego, CA, United States)
Fakhrai, H. (Salk Inst. for Biological Studies San Diego, CA, United States)
Lohrmann, R. (Salk Inst. for Biological Studies San Diego, CA, United States)
Orgel, L. E. (Salk Inst. for Biological Studies San Diego, CA, United States)
Van Roode, M. (Salk Institute for Biological Studies San Diego, CA, United States)
Date Acquired
August 10, 2013
Publication Date
January 1, 1981
Subject Category
SPACE BIOLOGY
Meeting Information
Origin of life(Jerusalem)
Funding Number(s)
CONTRACT_GRANT: NIH-GM-13435
CONTRACT_GRANT: NGR-05-067-001
Distribution Limits
Public
Copyright
Other