title: Angiotensin I-converting enzyme (ACE) inhibitory activities of sardinelle (Sardinella aurita) by-products protein hydrolysates obtained by treatment with microbial and visceral fish serine proteases.
abstract: The angiotensin I-converting enzyme (ACE) inhibitory activities of protein hydrolysates prepared from heads and viscera of sardinelle (Sardinella aurita) by treatment with various proteases were investigated. Protein hydrolysates were obtained by treatment with Alcalase(®), chymotrypsin, crude enzyme preparations from Bacillus licheniformis NH1 and Aspergillus clavatus ES1, and crude enzyme extract from sardine (Sardina pilchardus) viscera. All hydrolysates exhibited inhibitory activity towards ACE. The alkaline protease extract from the viscera of sardine produced hydrolysate with the highest ACE inhibitory activity (63.2±1.5% at 2mg/ml). Further, the degrees of hydrolysis and the inhibitory activities of ACE increased with increasing proteolysis time. The protein hydrolysate generated with alkaline proteases from the viscera of sardine was then fractionated by size exclusion chromatography on a Sephadex G-25 into eight major fractions (P1-P8). Biological functions of all fractions were assayed, and P4 was found to display a high ACE inhibitory activity. The IC50 values for ACE inhibitory activities of sardinelle by-products protein hydrolysates and fraction P4 were 1.2±0.09 and 0.81±0.013mg/ml, respectively. Further, P4 showed resistance to in vitro digestion by gastrointestinal proteases. The amino acid analysis by GC/MS showed that P4 was rich in phenylalanine, arginine, glycine, leucine, methionine, histidine and tyrosine. The added-value of sardinelle by-products may be improved by enzymatic treatment with visceral serine proteases from sardine.
authors.affiliation: Laboratoire de Génie Enzymatique et de Microbiologie - Ecole Nationale d'Ingénieurs de Sfax, B.P "W" 3038 Sfax, Tunisia.
authors.forename: Ali
authors.initials: A
authors.lastname: Bougatef
authors.affiliation: Laboratoire de Procédés Biologiques, Génie Enzymatique et Microbien, IUT A Lille I, BP 179, 59653 Villeneuve d'Ascq Cedex, France.
authors.forename: Naima
authors.initials: N
authors.lastname: Nedjar-Arroume
authors.affiliation: Laboratoire de Procédés Biologiques, Génie Enzymatique et Microbien, IUT A Lille I, BP 179, 59653 Villeneuve d'Ascq Cedex, France.
authors.forename: Rozenn
authors.initials: R
authors.lastname: Ravallec-Plé
authors.affiliation: CNRS Unité Mixte de Recherche 8576, Laboratoire de Glycobiologie Structurale et Fonctionnelle, Université des Sciences et Technologies de Lille, Bâtiment C9, 59655 Villeneuve d'Ascq Cedex, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Leroy
authors.affiliation: Laboratoire de Procédés Biologiques, Génie Enzymatique et Microbien, IUT A Lille I, BP 179, 59653 Villeneuve d'Ascq Cedex, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Guillochon
authors.affiliation: Laboratoire de Génie Enzymatique et de Microbiologie - Ecole Nationale d'Ingénieurs de Sfax, B.P "W" 3038 Sfax, Tunisia.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Barkia
authors.affiliation: Laboratoire de Génie Enzymatique et de Microbiologie - Ecole Nationale d'Ingénieurs de Sfax, B.P "W" 3038 Sfax, Tunisia. Electronic address: mon_nasri@yahoo.fr.
authors.forename: Moncef
authors.initials: M
authors.lastname: Nasri
keywords: ACE inhibitory activities; Enzymatic treatment; Protein hydrolysates; Sardine serine proteases; Sardinelle by-products