A homogeneous cyclic CMP phosphodiesterase hydrolyzes both pyrimidine and purine cyclic 2':3'- and 3':5'-nucleotides.
A homogeneous preparation of cyclic CMP phosphodiesterase (Helfman, D. M., Shoji, M., and Kuo, J. F. (1981) J. Biol. Chem. 256, 6327-6334) was found to catalyze the hydrolysis of both pyrimidine and purine cyclic 2':3'- and 3':5'-nucleotides. Hydrolysis of cyclic 2':3'-nucleotides resulted in the formation of both 2'- and 3'-nucleotides, although relative amounts of the products were variable. Hydrolysis of cyclic 2':3'-CMP or cyclic 2':3'-UMP yielded predominantly 3'-nucleotides. In contrast, hydrolysis of cyclic 2':3'-AMP produced equal amounts of 2'- and 3'-nucleotides, while the major product formed from cyclic 2':3'-GMP was 2'-nucleotide. When conventional pyrimidine and purine cyclic 3:5'-nucleotides were used as substrates, the enzyme hydrolyzed specifically the 3'-bond to yield only 5'-nucleotides. The relative rate of hydrolysis of cyclic 2':3'-nucleotides was cyclic CMP greater than cyclic UMP greater than cyclic GMP greater than or equal to cyclic AMP, respectively, whereas that for cyclic 3':5'-nucleotides was cyclic CMP greater than cyclic UMP greater than or equal to cyclic AMP greater than cyclic GMP, respectively. Furthermore, kinetic analysis suggested a single species of catalytic site on the enzyme may be involved in the hydrolysis of both pyrimidine and purine cyclic 2':3'- and 3':5'-nucleotides. These findings indicate that the present enzyme is the first multifunctional phosphodiesterase reported to date that is capable of hydrolyzing such a diversity of cyclic nucleotides.[1]References
- A homogeneous cyclic CMP phosphodiesterase hydrolyzes both pyrimidine and purine cyclic 2':3'- and 3':5'-nucleotides. Helfman, D.M., Kuo, J.F. J. Biol. Chem. (1982) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg