ACE (kininase II, EC 3.4.15.1) is a zinc dipeptidyl carboxypeptidase. ACE catalyses both angiotensin I transformation to angiotensis II (a potent vasopressor agent) and degradation of bradikinin, a vaso-depressor. ACE appears to play a key role in regulating vascular tone and remodeling the development of atherosclerotic lesions. Increasing evidence suggests that ACE plays an important role in vascular pathology. Recent studies shows two new functions of this important enzyme: 1) ACE enhances the presentation of endogenous antigens (in particularly HIV 1 gp160-derived peptide p18) to MHC class I-restricted T-lynphocytes (ref. 1); 2) amino-terminal domain of ACE cleaves effectively hemoregulatory tetrapeptide N-Ac-Ser-Asp-Lys-Pro (ref. 2,3) which is involved in the control of hemapoetic stem cell proliferation (the amount of this peptide greatly decreases in patients undergoing cancer chemotherapy) (ref. 4).
Activity:
~7mU/ ug of protein
(One unit will produce 1uMole of hippuric acid or His-Leu from Z-Phe-His-Leu per minute in 0.1M phosphate buffer, 30 mM sodium chloride, at pH 8.3 at 37 degrees C).
Applications:
Suitable for use as a reference in SDS-PAGE and Western blotting (together with anti-ACE monoclonal), as a reference antigen for immunoprecipitation, and as a source of pure ACE for different enzymatic studies of ACE. Other applications not tested.
Recommended Dilutions:
Western Blot: 500ng/lane if gel is developed with anti-ACE antibody. Optimal dilutions to be determined by the researcher.
Storage and Stability:
May be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Aliquots are stable for 6 months at -20 degrees 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.