[Conformational Fingerprinting Using Monoclonal Antibodies (on the Example of Angiotensin I-Converting Enzyme-ACE)]

Area of Science:

• Biochemistry and Molecular Biology
• Immunology
• Medical Diagnostics

Background:

• Monoclonal antibodies (mAbs) have been generated against human and other species' Angiotensin-Converting Enzyme (ACE) over 30 years.
• These mAbs were primarily used individually for ACE detection and quantification via various immunoassays.
• A hypothesis proposed that utilizing the entire set of mAbs against diverse ACE epitopes could yield novel insights into its structure and function.

Purpose of the Study:

• To explore the potential of using a comprehensive collection of mAbs targeting different ACE epitopes for novel structural and functional analysis.
• To establish a new methodology, 'conformational fingerprinting of ACE,' for deeper understanding of ACE.
• To investigate the tissue specificity of ACE and its potential diagnostic and therapeutic applications.

Main Methods:

• Generation and characterization of over 40 mAbs against structural and conformational epitopes of human, rat, and mouse ACE.
• Epitope mapping of all generated mAbs, with a focus on conformational epitopes.
• Application of the mAb set to study ACE conformational changes, mutations, and tissue-specific expression.

Main Results:

• Demonstrated that certain mAbs are highly sensitive to local conformational changes on the ACE surface, influenced by denaturation, inhibitors, or disease states.
• Successfully detected, localized, and characterized several human ACE mutations using the mAb set.
• Established the concept of 'conformational fingerprinting of ACE,' providing evidence for ACE tissue specificity and enabling targeted drug delivery to lung capillaries.

Conclusions:

• The comprehensive use of mAbs against diverse ACE epitopes provides a powerful tool for studying ACE structure, function, and conformational dynamics.
• Conformational fingerprinting of ACE offers a new avenue for understanding ACE tissue specificity, with significant scientific and diagnostic potential.
• This mAb-based conformational fingerprinting strategy is potentially applicable to other glycoproteins for generating organ-specific mAbs.