Abstract
Advantage was taken of the reversibility of the first step of ribonuclease-A action to synthesize the dinucleoside phosphorothioate Up(S)C from the crystalline isomer of uridine 2′,3′-cyclic phosphorothioate [Up̂(S)] and cytidine. Cyclic phosphorothioate was then reformed from Up(S)C by a nonenzymic reaction known to proceed by an in-line mechanism. The geometry of the enzymic reaction was determined to be in-line by a comparison of the Up̂(S) product with the Up̂(S) originally used. By the principle of microscopic reversibility, the geometry of the first step in the action of ribonuclease-A is shown to be in-line.
Keywords: in-line geometry; uridine 2′,3′-cyclic thiophosphate; 31P NMR
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Selected References
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