membrane protein agonist

Sphingosine-1-phosphate (S1P) is an agonist for S1P1-5 receptors and a ligand for GPR3, GPR6, and GPR12. As an intracellular second messenger, it mobilizes Ca2+ and acts as an extracellular ligand for G-protein coupled receptors. This important lipid mediator is generated from sphingosine or other membrane phospholipids.

Cholesterol is the primary sterol in mammals, accounting for approximately 20–25% of the plasma membrane structure. It plays a key role in regulating membrane fluidity, permeability, and protein function. As an endogenous agonist of estrogen-related receptor α (ERRα), cholesterol is widely involved in metabolic regulation and serves as a precursor for the synthesis of hormones and bile acids. It is commonly used in experimental models of hyperlipidemia.

Higenamine hydrochloride (norcoclaurine HCl) has been demonstrated to be a β2 adrenoreceptor agonist. Adrenergic receptors, or adrenoceptors, belong to the class of G protein–coupled receptors, and are the most prominent receptors in the adipose membrane, besides also being expressed in skeletal muscle tissue.