Pharmacological characterization of a novel non-AT1, non-AT2 angiotensin binding site identified as neurolysin

Abstract

The discovery of a novel non-AT1, non-AT2 binding site for angiotensins in the rodent brain and testis that is unmasked by the organomercurial compound para-chloromercuribenzoic acid (PCMB) has catalyzed efforts to purify and characterize this protein. We recently reported that this protein is neurolysin and now report upon the specificity of this binding site for various neuropeptides. Competition binding assays in rat brain and testis used 125I-Sar1, Ile8 angiotensin II (Ang II) as the radioligand in the presence of saturating concentrations of AT1 and AT2 receptor antagonists and 100 µM parachloromercuribenzoate. Primary screening of 36 peptides and other compounds at 10 µM concentration revealed seven peptides that inhibited specific binding > 50%: ghrelin, Tyr1 S36057 (a melanin-concentrating hormone receptor ligand), orphanin FQ and its congeners (Tyr1 and Tyr14), Dynorphin A (1–8), and Ang (1–9). The selective neurolysin inhibitor Proline-Isoleucine dipeptide was inactive at 1 mM. These results suggest that the ability of PCMB to unmask high affinity binding of Ang II to neurolysin is a pharmacological effect and that neurolysin may significantly affect the activity of the reninangiotensin system.

Rational Drug Design and Synthesis of Molecules Targeting the Angiotensin II Type 1 and Type 2 Receptors

“…Also, the different metabolites of Ang II, which form after proteolytic degradation of the parent molecule, present biological activity. In addition, Ang II has high binding affinity to neurolysin which in turn may affect significantly the activity on RAS [5,6,7]. The action of Ang II on AT 1 R was the first to be studied in detail, while the mode of action of AT 2 R remained elusive for a long time owing to the lack of ligands that selectively target this receptor as also due to its low expression [8,9,10,11].…”

Δυναμικές Ιδιότητες Της Ολμεσαρτάνης Στο Διάλυμα Και Στο Ενεργό Κέντρο Του Υποδοχέα Τύπου 1 Της Αγγειοτασίνης ΙΙ

“…Also, the different metabolites of Ang II, which are formed after proteolytic degradation of the parent molecule, exert biological activities. In addition, Ang II has high binding affinity to neurolysin which in turn may affect significantly the activity on RAS [6][7][8] . The action of Ang II on AT 1 R was the first to be studied in detail, while the mode of action of AT 2 R remained elusive for a long time owing to the lack of ligands that selectively target this receptor as also due to its low expression [9][10][11][12] .…”

“…In order to amplify the applicability of water-soluble CAs in complex systems, Liu et al 182,183 reported the complexation of topotecan and irinotecan with psulphonatocalix [4]arene under 1:1 molar ratio, and the inclusion modes were confirmed by means of 1 H NMR, DSC, 2D NMR and UV-vis spectroscopy. And then Song et al 184 constructed the inclusion complex using p-sulphonatocalix [6]arene and vitamin B6 in acidic and alkaline media. The complex systems could release cargo through disaggregation of the inclusion complexes under certain conditions, which means they can act as an excellent candidate for drug delivery.…”