Deoxyadenosine Diphosphate as a Substrate and Inhibitor of Polynucleotide Phosphorylase of Micrococcus luteus
Year: 1971
Type: article
Abstract: dADP inhibits de novo polymerization of ADP by polynucleotide phosphorylase (primer-independent, Form I, and primer-dependent, Form T, enzyme). Inhibition occurs at concentrations of dADP 2 orders of magnitude lower than the ADP concentration. Adenosine methylene diphosphonate, another analogue of ADP, does not inhibit polymerization of ADP at comparable concentrations. Although de novo polymerization is very sensitive to low concentrations of dADP, the addition of nucleoside monophosphate units to oligonucleotide primers is only inhibited at high concentrations of dADP. Thus oligonucleotides appear to relieve the inhibition. When Mg2+ is replaced by Mn2+, the sensitivity of the enzyme to dADP is markedly reduced. These results are interpreted to indicate that dADP specifically inhibits chain by interaction with enzyme at an initiation site. Values of the association constants for formation of complexes between Mg2+ and Mn2+ with dADP and adenosine methylene diphosphonate are presented.
Source: Journal of Biological Chemistry
Authors: Janice Yang Chou, Maxine F. Singer
Institution: National Institutes of Health
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W1663318878