Meena, Laxman S. and Dhakate, Sanjay R. and Sahare, Purushottam D. (2012) Elucidation of Mg2+ binding activity of adenylate kinase from Mycobacterium tuberculosis H(37)Rv using fluorescence studies. Biotechnology and Applied Biochemistry, 59 (6). pp. 429-436. ISSN 0885-4513
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Abstract
Adenylate kinase (AK) is a small ubiquitous enzyme that catalyzes the reversible transfer of the terminal phosphate group from adenine triphosphate (ATP): magnesium ion (Mg2+) to adenine monophosphate (AMP) to form two molecules of adenine diphosphate (ADP). AK thus maintains the homeostasis of adenine nucleotides in eukaryotes and prokaryotes. Because the [ATP]/[ADP] ratio is an important parameter in energy regulation in cells, Mg2+-activated AK has an important biological role, particularly in the case of bacteria, as imbalance in the ratio of [ATP]/[ADP] has been associated with alteration in its DNA supercoiling state. In the present study, magnesium-binding assays were carried out by systematically varying the concentrations of Mg2+, protein, AMP, ATP, and indicator in kinetic experiments. We report evidence that during magnesium-binding assay, the fluorescence level of the indicator Mag-Indo-1 changes with protein concentration, suggesting that magnesium ions are binding to AK. The dual activity of AK both as nucleoside monophosphate and diphosphate kinases suggests that this enzyme may have a role in RNA and DNA biosynthesis in addition to its role in intracellular nucleotide metabolism. According to the proposed model, the magnesium-activated AK exhibits an increase in its forward reaction rate compared with the inactivated form. These findings imply that Mg2+ could be an important regulator in the energy signaling network in cells.
Item Type: | Article |
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Additional Information: | Copyright for this article belongs to M/s Wiley. |
Subjects: | Biochemistry & Molecular Biology Biotechnology & Applied Microbiology |
Divisions: | UNSPECIFIED |
Depositing User: | Users 27 not found. |
Date Deposited: | 04 Mar 2020 11:33 |
Last Modified: | 04 Mar 2020 11:33 |
URI: | http://npl.csircentral.net/id/eprint/3590 |
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