Renin-Angiotensin System (RAS) is a crtical regulator of blood pressure homeostasis. The protease renin cleaves angiotensinogen into inactive decameric peptide angiotensin-I (Ang-I). Angiotensin-converting enzyme (ACE) then cleaves C-terminal dipeptide from Ang-I to form an active octamer angiotensin-II (Ang-II), which can contribute to hypertension by promoting vascular smooth muscle vasocontriction and renal tubule sodium reabsorption. ACE can also cleave many other small peptides including the vasodialating peptide bradykinin into inactive fragment, cleave Alzheimer amyloid beta-peptide (Abeta), retard Abeta aggregation, deposition and fibril formation. ACE mutant mice display spontaneous hypotension, partial male infertility and kidney malformations. ACE is found in somatic (s-ACE) and testicular/germinal (t-ACE) isoforms. The products of renin and ACE catalysis, namely Ang1-10 and Ang1-8 can also be by another peptidase, ACE-2 to Ang1-9 and Ang1-7, respectively. ACE-2 and ACE (s-ACE and t-ACE) are made as transmembrane (TM) proteins but these enzymes also exist as soluble, truncated forms lacking the TM and cytosolic domains.
ACE-2 (also known as ACE-2 and ACE homolog, ACEH) gene has been mapped at human chromosome Xp22. ACE-2 enzymes from human (805aa) and mouse (798aa) are single chain proteins with 40% seq homology to N- and C-terminal domains of ACE. However, in contrast to s-ACE which consists of two catalytic sites, ACE-2 contains only one active site. Unlike s-ACE and t-ACE which are dipeptidyl-carboxypeptidases, ACE-2 acts as a carboxypeptidase, cleaving single residue from Ang-I, generating Ang1-9 and a single residue from Ang-II to generate Ang1-7. ACE-2 can cleave angiotensin-I but not bradykinin and the enzyme activity is not inhibited by the ACE inhibitors. This enzyme is expressed highly in heart, kidney and testis and moderately in colon, small intestine and ovary. ACE-2 is an essential regulator of heart fuction because targeted disruption of this enzyme in mice results in severe cardiac contractility defect, increased angiotensin-II levels and upregulation of hypoxia-induced genes in the heart.
Human ACE-2 (1-740aa, glycosylated secreted protein of MW ~120kD, predicted MW 85kD) with His tag was expressed in mouse myeloma cell line NS0 and purified >90% (SDS-PGE).
Applications
Suitable for use in ELISA, Western Blot. Other applications not tested.
Recommended Dilution
Western Blot: 1-10ug/ml. Recognize ~120kD ACE-2 under reducing and non-reducing conditions. ELISA: 0.5-1ug/ml. Coat ELISA plates at 1ug/ml Control Peptide.
Optimal dilutions to be determined by the researcher.
Control Peptide: A2295-01J1 and A2295-01S.
Storage and Stability
May be stored at 4°C for short-term only. For long-term storage, store at -20°C. Aliquots are stable for at least 12 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
Immunogen
Synthetic peptide (489-508aa) of Human ACE-2.
Form
Supplied as a liquid in PBS, pH 7.4 and 0.09% sodium azide, 40% glycerol.
Purity
Purified by immunoaffinity chromatography.
Specificity
Recognizes Angiotensin Converting Enzyme 2. Species crossreactivity: Human. Sequence homology: Mouse: 95%. Antibody crossreactivity in various species is not known.