Conformational fingerprint of blood and tissue ACEs: Personalized approach.

Larisa M Samokhodskaya,Leo A Bokeria,Victoria E Tikhomirova,Alexander V Balatsky,Olga A Kost,Naida I Bulaeva,Olga V Kryukova,Elena Z Golukhova,Sergei M Danilov

doi:10.1371/journal.pone.0209861

Abstract

BackgroundThe pattern of binding of monoclonal antibodies (mAbs) to 18 epitopes on human angiotensin I-converting enzyme (ACE)–“conformational fingerprint of ACE”–is a sensitive marker of subtle conformational changes of ACE due to mutations, different glycosylation in various cells, the presence of ACE inhibitors and specific effectors, etc.Methodology/Principal findingsWe described in detail the methodology of the conformational fingerprinting of human blood and tissue ACEs that allows detecting differences in surface topography of ACE from different tissues, as well detecting inter-individual differences. Besides, we compared the sensitivity of the detection of ACE inhibitors in the patient’s plasma using conformational fingerprinting of ACE (with only 2 mAbs to ACE, 1G12 and 9B9) and already accepted kinetic assay and demonstrated that the mAbs-based assay is an order of magnitude more sensitive. This approach is also very effective in detection of known (like bilirubin and lysozyme) and still unknown ACE effectors/inhibitors which nature and set could vary in different tissues or different patients.Conclusions/SignificancePhenotyping of ACE (and conformational fingerprinting of ACE as a part of this novel approach for characterization of ACE) in individuals really became informative and clinically relevant. Appreciation (and counting on) of inter-individual differences in ACE conformation and accompanying effectors make the application of this approach for future personalized medicine with ACE inhibitors more accurate. This (or similar) methodology can be applied to any enzyme/protein for which there is a number of mAbs to its different epitopes.

Highlights

Angiotensin I-converting enzyme (ACE, CD143, EC 3.4.15.1), a zinc-metallopeptidase, is a key regulator of blood pressure participating in the development of vascular pathology and remodeling
In order to quantify the amount of immunoreactive angiotensin I-converting enzyme (ACE) protein and to analyze the changes in the local ACE surface conformation we used enzyme (ACE) immune-capture assay with panel of monoclonal antibodies (mAbs) to different epitopes on the surface of N- and C domains of ACE [16, 19]
High-binding 96-well plate was coated with different mAbs to ACE via goat-anti-mouse IgG bridge (10 μg/ml, 50 μl in each well) in PBS

Summary

Background

The pattern of binding of monoclonal antibodies (mAbs) to 18 epitopes on human angiotensin I-converting enzyme (ACE)–“conformational fingerprint of ACE”–is a sensitive marker of subtle conformational changes of ACE due to mutations, different glycosylation in various cells, the presence of ACE inhibitors and specific effectors, etc. We compared the sensitivity of the detection of ACE inhibitors in the patient’s plasma using conformational fingerprinting of ACE (with only 2 mAbs to ACE, 1G12 and 9B9) and already accepted kinetic assay and demonstrated that the mAbs-based assay is an order of magnitude more sensitive This approach is very effective in detection of known (like bilirubin and lysozyme) and still unknown ACE effectors/inhibitors which nature and set could vary in different tissues or different patients. Appreciation (and counting on) of inter-individual differences in ACE conformation and accompanying effectors make the application of this approach for future personalized medicine with ACE inhibitors more accurate This (or similar) methodology can be applied to any enzyme/protein for which there is a number of mAbs to its different epitopes

Introduction

Materials and methods

Results and discussion