Enzima conversora de angiotensina 1 : purificação, imobilização e bioconjugação
Abstract
Angiotensin converting enzyme 1 (ACE1) is a dipeptidyl carboxypeptidase that
converts angiotensin I (decapeptide) to a vasoconstrictor octapeptide angiotensin
II. Thus, ACE presents an important role in blood pressure regulation. There are
many synthetic commercially available ACE inhibitors such as captopril, lisinopril
and enalapril. Due to their side effects, naturally occurring inhibitors have been
prospected. In order to endorse this research field we have developed a new tool
for ACE ligand screening. To this end, ACE was extracted from bovine lung,
purified and chemically immobilized in modified ferrite magnetic beads (ACEMBs).
The ACE-MBs have shown a Michaelian kinetic behavior towards hippurylhistidyl-
leucine (HHL) and was also able to catalyze the conversion of angiotensin
I to angiotensin II. Moreover, as proof of concept, the ACE-MBs was inhibited by
lisinopril with an IC50 of 10 nM. At the fishing assay, ACE-MBs were able not only
to fish out the reference inhibitor, but also three peptides from a pool of tryptic
digested BSA. ACE-MBs emerge as new straightforward tool for ACE kinetics
determination, inhibition and binder screening.