Related Experiment Video
Updated: Aug 24, 2026

HPLC-based Assay to Monitor Extracellular Nucleotide/Nucleoside Metabolism in Human Chronic Lymphocytic Leukemia Cells
Published on: July 20, 2016
S-Adenosylhomocysteine hydrolase as a target for intracellular adenosine action
1Department of Pharmacology and Toxicology, Faculty of Medicine, University of Tübingen, Wilhelmstrasse 56, D-72074 Tübingen, Germany. doris.kloor@uni-tuebingen.de
Abstract:
S-Adenosylhomocysteine hydrolase (AdoHcyase) controls intracellular levels of S-adenosylhomocysteine (AdoHcy). AdoHcy is a potent product inhibitor of some S-adenosylmethionine-dependent methyltransferases. Pharmacological modulation of AdoHcyase to indirectly inhibit methyltransferases can be guided by the fact that adenosine binds with high affinity to AdoHcyase and inhibits enzyme activity. cAMP can compete with adenosine and can counteract the adenosine-induced inhibition of AdoHcyase. Thus, the ratio between adenosine and cAMP, which can vary under different physiological conditions, might result in changes in, for example, DNA promoter methylation and therefore transcription.
More Related Videos
Related Concept Videos
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
RNA Editing
Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
Adrenergic Agonists: Indirect-Acting Agents
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
Drugs Affecting Neurotransmitter Synthesis

