Distinct functions of cardiac β-adrenergic receptors in the T-tubule vs<i>.</i> outer surface membrane.

ABSTRACT: β-Adrenoceptors (β-ARs) regulate cardiac function during sympathetic nerve stimulation. β-ARs are present in both the cardiac T-tubule (TTM) and outer surface membrane (OSM), but how their location impacts their function is unknown. Here, we developed a technology based on size exclusion to explore the function of β-ARs located in the OSM. We synthesized a PEG-Iso molecule by covalently linking isoprenaline (Iso) to a 5000 Da PolyEthylene-Glycol (PEG) chain to increase the size of the β-AR agonist and prevent it from accessing the T-tubule network. The affinity of PEG-Iso and Iso on β₁- and β₂-ARs was measured using radioligand binding. Molecular dynamics simulation was used to assess PEG-Iso conformation and visualize the accessibility of the Iso moiety to water. Usi

SUBMITTER: Madders GWP 

PROVIDER: S-EPMC12578441 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature