A homogeneous cyclic CMP phosphodiesterase hydrolyzes both pyrimidine and purine cyclic 2':3'- and 3':5'-nucleotides.
Year: 1982
Type: article
Abstract: 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.
Source: Journal of Biological Chemistry
Authors: D.M. Helfman, J.F. Kuo
Institution: Emory University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W1507399535