Angiotensin II (Ang-II) is a key signalling peptide of the renin angiotensin system (RAS) which is involved in regulating functions such as blood pressure, cardiovascular function and energy balance. RAS activity is elevated in obesity and is widely studied in relation to lifestyle-related diseases.
Ang-II is produced from angiotensinogen (AGT) via the intermediate angiotensin I (Ang-I). AGTis cleaved by the aspartyl-protease, renin, to produce Ang-I, which is then cleaved by the dicarboxyl-peptidase angiotensin converting enzyme (ACE), which removes a histidine and a leucine, from the C-terminus of Ang-I to form Ang-II.
Ang-II exerts its affect by binding to the G-protein-coupled receptors; Ang II type 1 (AT1) and Ang II type 2 (AT2) receptors. Ang-II plays central roles in glucose metabolism and blood pressure. Increased levels of Ang-II have also been associated with Alzheimer’s disease, and certain cancers including oesophageal squamous cell carcinoma (ESCC), brain cancers and breast cancer. The effects of Ang-II appear to be supressed or limited by another branch of the RAS; the ACE2/Ang-(1-7)/Mas pathway.
The isoleucine residue at position 5 of this peptide is isotopically labelled with carbon-13 (6) and nitrogen-15 (1), giving this peptide a mass increase of 7 compared to the unlabelled peptide