Time filter

Source Type

Villeneuve-la-Rivière, France

Adje E.Y.,Laboratoire Of Procedes Biologiques | Balti R.,Laboratoire Of Procedes Biologiques | Balti R.,University of Sfax | Kouach M.,Laboratoire Dapplication Of Spectrometrie Of Masse | And 3 more authors.
International Journal of Biological Macromolecules | Year: 2011

Under standard conditions, the peptides and specially the active peptides were obtained from either the denatured hemoglobin that all structures are completely modified or either the native hemoglobin where all structures are intact. In these conditions, antibacterial peptides were isolated from a very complex peptidic hydrolysate which contains more than one hundred peptides having various sizes and characteristics, involving a complex purification process. The new hydrolysis conditions were obtained by using 40% methanol, 30% ethanol, 20% propanol or 10% butanol. These conditions, where only the secondary structure of hemoglobin retains intact, were followed in order to enrich the hydrolyzed hemoglobin by active peptides or obtain new antibacterial peptides. In these controlled peptic hydrolysis of hemoglobin, a selective and restrictive hydrolysate contained only 29 peptides was obtained. 26 peptides have an antibacterial activity against Micrococcus luteus, Listeria innocua, and Escherichia coli with MIC from 187.1 to 1 μM. Among these peptides, 13 new antibacterial peptides are obtained only in these new hydrolysis conditions. © 2011 Elsevier B.V. Source

Balti R.,University of Sfax | Jridi M.,University of Sfax | Sila A.,University of Sfax | Souissi N.,University of Sfax | And 3 more authors.
Food Hydrocolloids | Year: 2011

The characteristics and functional properties of gelatin from skin cuttlefish (Sepia officinalis) were investigated and compared to those of halal bovine gelatin (HBG). The gelatin extraction efficiency was improved by an acid-swelling process in the presence of smooth hound crude acid protease extract (SHCAP). The yields of gelatins from cuttlefish skin after 48. h with acid and with crude acid protease (15. units/g alkaline-treated skin) were 2.21% and 7.84%, respectively. The gelatin from skin cuttlefish had high protein (91.35%) but low fat (0.28%) contents. Compared to HBG, the cuttlefish-skin gelatin (CSG) has different amino acids composition than halal bovine gelatin. CSG contained slightly low hydroxyproline and proline (180‰) than HBG (219‰), whereas the content of serine was higher (49‰ versus 29‰). The gel strength of the gelatin gel from CSG (181. g) was lower than that of HBG (259. g) (p < 0.05) possibly due to lower hydroxyproline content. Cuttlefish-skin gelatin exhibited a similar emulsifying activity but greater emulsifying and foam stability than the halal bovine gelatin (p < 0.05). Foam formation ability, foam stability and water-holding capacity of CSG were slightly lower than those of the HBG, but fat-binding capacity was higher in the cuttlefish gelatin. © 2010 Elsevier Ltd. Source

Nasri R.,University of Sfax | Amor I.B.,Sanguine | Bougatef A.,University of Sfax | Nedjar-Arroume N.,Laboratoire Of Procedes Biologiques | And 4 more authors.
Food Chemistry | Year: 2012

The anticoagulant activities of protein hydrolysates prepared from goby muscle by treatment with various bacterial alkaline proteases were investigated. All proteases exhibited varying degrees of hydrolysis (DH) and all goby protein hydrolysates (GPHs) caused a significant prolongation of both the thrombin time (TT) and the activated partial thromboplastin time (APTT). The hydrolysate generated by the crude protease from Bacillus licheniformis NH1 displayed the highest anticoagulant activity, and the higher TT (about 32 s) at a concentration of 5 mg/mL was obtained with hydrolysate having a DH of 8.86%. This hydrolysate was then fractionated by size exclusion chromatography on a Sephadex G-25 column into five major fractions (F1-F5). Fraction F2, which exhibited the highest anticoagulant activity, was then fractionated by reversed-phase high-performance liquid chromatography. The molecular masses and amino acid sequences of four peptides in peptide sub-fraction F2-6, which exhibited the highest anticoagulant activity, were determined using ESI-MS and ESI-MS/MS, respectively. The structures of these peptides were identified as Leu-Cys-Arg, His-Cys-Phe, Cys-Leu-Cys-Arg and Leu-Cys-Arg-Arg. © 2012 Elsevier Ltd. All rights reserved. Source

Sila A.,University of Sfax | Sila A.,Laboratoire Of Procedes Biologiques | Nedjar-Arroume N.,Laboratoire Of Procedes Biologiques | Hedhili K.,Laboratoire Of Procedes Biologiques | And 5 more authors.
LWT - Food Science and Technology | Year: 2014

Peptides obtained by enzymatic hydrolysis of fish proteins exhibit not only nutritional but also biological properties of dietary uses, or even therapeutic potential. The objective of the present study was to isolate and characterize peptides from the protein hydrolysates of barbel muscle with antibacterial activity against Gram-positive (Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Micrococcus luteus and Bacillus cereus) and Gram-negative (Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Klebsiella pneumoniae and Enterobacter sp.) bacteria. Barbel muscle protein hydrolysates (BMPHs), obtained by treatment with Alcalase® (DH=6.6%), was fractionated by size exclusion chromatography on a Sephadex G-25 and purified by reversed-phase high performance liquid chromatography (RP-HPLC). The molecular masses and amino acid sequences of these peptides were determined using ESI-MS and ESI-MS/MS, respectively. Eleven peptides in FII-1, FII-2, FII-3 and FII-4 sub-fractions separated by RP-HPLC were identified. The most active peptide fraction (FII-3) contained three peptides: Ala-Ala-Ala-Leu; Ala-Ala-Gly-Gly-Val and Ala-Ala-Val-Lys-Met.These peptides don't show hemolytic activity towards bovine erythrocytes. These results suggest that some peptides from barbel could be a beneficial ingredient for nutraceuticals. © 2013 Elsevier Ltd. Source

Adje E.Y.,Laboratoire Of Procedes Biologiques | Balti R.,Laboratoire Of Procedes Biologiques | Balti R.,University of Sfax | kouach M.,Laboratoire Dapplication Of Spectrometrie Of Masse | And 2 more authors.
European Food Research and Technology | Year: 2011

Protein hydrolysates are of a significant interest, due to their potential application as a source of bioactive peptides in nutraceutical and pharmaceutical domains. The present study was focused on bovine hemoglobin hydrolysate obtained with pig pepsin in the presence of 30% ethanol. This hydrolysate was fractioned by reversed-phase high-performance liquid chromatography (RP-HPLC) into 12 major fractions (F1-F12). All fractions were analyzed by ESI/MS and ESI/MS/MS, in order to characterize and identify the peptides in these fractions. This hydrolysis permitted to generate a new serial of bioactive peptides with both antimicrobial and ACE inhibitory activities. Identified peptides were TKAVEHLDDLPGALSELSDLHAHKLRVDPVNFKLLSHSLL, LDDLPGALSELSDLHAHKLRVDPVNFKLLSHSL, KLLSHSL, and LLSHSL corresponding respectively to the 67-106, 73-105, 99-105, and 100-105 fragments of the α chain of bovine hemoglobin. They were the first found from bovine hemoglobin. These purified peptides have an antibacterial activity against four bacteria strains: Kocuria luteus A270, Listeria innocua, Escherichia coli, and Staphylococcus aureus with a MIC between 187.1 and 35.2 μM. On the other hand, these peptides displayed at the same time ACE inhibitory activity with an IC50 range from 42.55 to 1,095 μM. © 2011 Springer-Verlag. Source

Discover hidden collaborations