Effect ofJatropha curcasPeptide Fractions on the Angiotensin I-Converting Enzyme Inhibitory Activity

Abstract

Hypertension is one of the most common worldwide diseases in humans. Angiotensin I-converting enzyme (ACE) plays an important role in regulating blood pressure and hypertension. An evaluation was done on the effect of Alcalase hydrolysis of defatted Jatropha curcas kernel meal on ACE inhibitory activity in the resulting hydrolysate and its purified fractions. Alcalase exhibited broad specificity and produced a protein hydrolysate with a 21.35% degree of hydrolysis and 34.87% ACE inhibition. Ultrafiltration of the hydrolysate produced peptide fractions with increased biological activity (24.46–61.41%). Hydrophobic residues contributed substantially to the peptides' inhibitory potency. The 5–10 and <1 kDa fractions were selected for further fractionation by gel filtration chromatography. ACE inhibitory activity (%) ranged from 22.66 to 45.96% with the 5–10 kDa ultrafiltered fraction and from 36.91 to 55.83% with the <1 kDa ultrafiltered fraction. The highest ACE inhibitory activity was observed in F2 (IC50 = 6.7 μg/mL) from the 5–10 kDa fraction and F1 (IC50 = 4.78 μg/mL) from the <1 kDa fraction. ACE inhibitory fractions from Jatropha kernel have potential applications in alternative hypertension therapies, adding a new application for the Jatropha plant protein fraction and improving the financial viability and sustainability of a Jatropha-based biodiesel industry.

Physicochemical Properties and ACE‐I Inhibitory Activity of Protein Hydrolysates from a Non‐Genetically Modified Soy Cultivar

“…The enzyme Alcalase was chosen for this study due to its broad specificity and high activity, compared to other proteases, which had been reported by Seo et al [33] and Segura-Campos et al [19]. Figure 1 shows the hydrolysis profile of SPI obtained by treating with two different Alcalase concentrations, 0.5 AU (1.6 µL/g) and 1.0 AU (3.2 µL/g),…”

“…IC 50 = (50 −b)/m, respectively, at 50 °C. These levels were selected based on previous studies that used levels ranging from 0.3 and 1.5 AU on proteins in order to produce various sized peptides [19,25]. One Anson unit (AU) is defined as that amount of enzyme which will digest (under specific conditions) ureadenatured hemoglobin to release a tricholoroacetic acid soluble product per minute and gives the same color with Folin-Ciocalteau Phenol reagent as one milli-equivalent of tyrosine at 30 °C and pH 7.5 [34].…”

“…One Anson unit (AU) is defined as that amount of enzyme which will digest (under specific conditions) ureadenatured hemoglobin to release a tricholoroacetic acid soluble product per minute and gives the same color with Folin-Ciocalteau Phenol reagent as one milli-equivalent of tyrosine at 30 °C and pH 7.5 [34]. The incubation temperature, 50 °C, was chosen because it has been used in previous studies as the optimal temperature for Alcalase activity resulting in higher protein yield in comparison to an incubation temperature of 22 °C (ambient) [12,19].…”

“…Alcalase contains serine in its active center that cleaves most peptide bonds, with a preference on the carboxyl side of hydrophobic amino acids [13,14]. Alcalase has been used extensively to prepare a wide array of protein hydrolysates from soybean protein, chickpea protein, lima bean protein, and fish protein [15][16][17][18][19]. Furthermore, the functionality of the hydrolyzed product can be controlled by selection of specific reaction conditions [11].…”

A new peptide from Jatropha curcas seeds: Unusual sequence and insights into its synthetic analogue that enhances proteolytic activity of papain

“…More recently, it was published a study describing a rich source of bioactive peptides generated from protein hydrolysis that was able to inhibit the angiotensin, an enzyme involved in blood pressure control [9]. The field of finding polypeptides from plant biomass, even in rich sources such as species from the genus Jatropha is full of drawbacks to be explored, mainly due to sample preparation, appropriate fractionation and identification methods [10,11].…”