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Published on: September 28, 2015
Angioprotectin: an angiotensin II-like peptide causing vasodilatory effects
Vera Jankowski1, Markus Tölle, Robson A S Santos
1Medizinische Klinik IV, Charité-Universitätsmedizin Berlin, Berlin, Germany.
Summary
A novel angiotensin II-like peptide, angioprotectin, was discovered in human plasma. This peptide acts as a Mas receptor agonist, antagonizing angiotensin II
Area of Science:
- Cardiovascular Research
- Endocrinology
- Peptide Chemistry
Background:
- The renin-angiotensin system (RAS) includes various angiotensin peptides, primarily fragments of angiotensin II (Ang II).
- These fragments exhibit diverse affinities for known angiotensin receptors.
- Understanding novel peptides within the RAS is crucial for cardiovascular and renal physiology.
Purpose of the Study:
- To identify and characterize a novel endogenous octapeptide in human plasma with Ang II-like activity.
- To investigate the functional role and receptor interactions of this new peptide.
- To assess its potential contribution to measured Ang II levels.
Main Methods:
- Plasma samples from healthy humans and patients with end-stage renal failure were analyzed.
- Chromatographic purification and MALDI-TOF/TOF mass spectrometry were used for structural identification.
- Functional assays using rat aortic rings and receptor binding studies were performed.
Main Results:
- A novel octapeptide, angioprotectin (Pro-Glu-Val-Tyr-Ile-His-Pro-Phe), was identified.
- Angioprotectin acts as a potent Mas receptor agonist, stronger than Ang 1-7, and antagonizes Ang II's vasoconstrictive effects.
- Plasma angioprotectin levels were ~15% of Ang II in healthy individuals, increasing to 50% in renal failure patients; it is not distinguished by common Ang II antibodies.
Conclusions:
- Angioprotectin is a novel, biologically active peptide within the human RAS.
- Its Mas receptor agonism and antagonism of Ang II effects suggest a significant physiological role.
- Angioprotectin may influence measured Ang II concentrations, impacting diagnostic interpretations.
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