title: Affinity purification of copper-chelating peptides from sunflower protein hydrolysates.
abstract: Copper-chelating peptides were purified from sunflower protein hydrolysates by affinity chromatography using immobilized copper. A variety of protein hydrolysates were obtained by incubation with the proteases Alcalase and Flavourzyme for different periods of time. Chelating activity was indirectly determined by measuring the inhibitory effect of hydrolysates on the oxidation of beta-carotene by copper. Copper-binding peptides purified from the two hydrolysates that inhibited oxidation by copper the most contained 25.4 and 42.0% histidine and inhibited beta-carotene oxidation 8 and 3 times more than the original hydrolysates, which had 2.4 and 2.6% histidine, respectively. Thus, histidine content is not the only factor involved in antioxidant activity, and probably other factors such as peptide size and amino acid sequence are also important. This work shows that affinity chromatography can be used for the purification of copper-chelating peptides and probably other metals of nutritional interest such as calcium, iron, and zinc. In addition to their antioxidant potential, chelating peptides are of nutritional interest because they increase bioavailability of minerals.
authors.affiliation: Instituto de la Grasa (CSIC), Avenida Padre García Tejero 4, 41012 Sevilla, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Megías
authors.forename: Justo
authors.initials: J
authors.lastname: Pedroche
authors.forename: Maria M
authors.initials: MM
authors.lastname: Yust
authors.forename: Julio
authors.initials: J
authors.lastname: Girón-Calle
authors.forename: Manuel
authors.initials: M
authors.lastname: Alaiz
authors.forename: Francisco
authors.initials: F
authors.lastname: Millan
authors.forename: Javier
authors.initials: J
authors.lastname: Vioque
mesh_terms: D002614:Chelating Agents / Q000302:isolation & purification* / Q000494:pharmacology; D002846:Chromatography, Affinity; D003300:Copper / Q000737:chemistry*; D006368:Helianthus / Q000737:chemistry*; D010455:Peptides / Q000302:isolation & purification* / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry*; D011492:Protein Hydrolysates / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D010455:Peptides; D010940:Plant Proteins; D011492:Protein Hydrolysates; D003300:Copper