"Bottom-Up" Strategy for the Identification of Novel Soybean Peptides with Angiotensin-Converting Enzyme Inhibitory Activity.

Luca Dellafiora,Anna Arnoldi,Carlotta Bollati,Raffaele Pugliese,Carmen Lammi,Fabrizio Gelain,Gianni Galaverna

doi:10.1021/acs.jafc.9b07361

Abstract

IAVPTGVA (Soy1) and LPYP are two soybean peptides, which display a multifunctional behavior, showing in vitro hypocholesterolemic and hypoglycemic activities. A preliminary screening of their structures using BIOPEP suggested that they might be potential angiotensin-converting enzyme (ACE) inhibitors. Therefore, a bottom-up-aided approach was developed in order to clarify the in vitro hypotensive activity. Soy1 and LPYP dropped the intestinal and renal ACE enzyme activity with IC50 values equal to 14.7 ± 0.28 and 5.0 ± 0.28 μM (Caco-2 cells), and 6.0 ± 0.35 and 6.8 ± 0.20 μM (HK-2 cells), respectively. In parallel, a molecular modeling study suggested their capability to act as competitive inhibitors of this enzyme. Finally, in order to increase both their stability and hypotensive properties, a suitable strategy for the harmless control of their release from a nanomaterial was developed through their encapsulation into the RADA16-assembling peptide.

Highlights

Hypertension is one of the main risk factors for the development of cardiovascular diseases.[1]
Angiotensin-converting enzyme (ACE, EC 3.4.15.1), a dipeptidyl-carboxypeptidase expressed in many tissues, is a key enzyme for blood pressure regulation, being responsible of the conversion of inactive angiotensin I (Ang) into active Ang II, a vasoconstrictive octapeptide that is accountable for hypertension progression.[4]
This is true in the field of hypotensive food peptides: several peptides from milk, meat, egg, fish, lupin, and soybean sources have been singled out as inhibitors of the angiotensin-converting enzyme (ACE) activity.[5−8] Milk proteins have a leading role as a source of ACE inhibitory peptides: in particular, VPP (Val-Pro-Pro) and IPP (Ile- Pro-Pro), two peptides derived from β-casein and κcasein, are the most active ACE inhibitors from any food source;[9] their hypotensive effect has been confirmed in vivo in spontaneously hypertensive rats (SHR) fed with sour milk and they are on the market as ingredients of antihypertensive drinks, such as the Japanese “Calpis” and the Finnish “Evolus”

Summary

Introduction

Hypertension is one of the main risk factors for the development of cardiovascular diseases.[1]. IAVPTGVA (Soy1) and LPYP are peptides derived from the hydrolysis of soybean glycinin with pepsin and trypsin,[11] respectively, which have been demonstrated to be absorbable in Caco[2] cell monolayers.[12] In more detail, recent evidence suggests that both peptides are absorbed by differentiated Caco-2 cells as a function of time and that Soy[1] is better absorbed than LPYP after 2 h of incubation in the apical side of monolayers.[12] Mature enterocytes represent the first physiological barrier that bioactive food peptides encounter after ingestion; their absorption is a dynamic process which co-exists with their metabolic degradation. In light of this observation, some evidence underlines that during its absorption, Soy[1] (IAVPTGVA) is partially metabolized by active Caco-2 cell membrane peptidases in three breakdown fragments (AVPTGVA, IAVP, and IAV), which are absorbed in the same cellular system.[12]

Objectives

Methods

Results