Screening and Purification of Metal Chelating Peptides in Hydrolysates for their Antioxidant Properties

Abstract

Metal-chelating peptides obtained after protein hydrolysis exhibit antioxidant properties used in pharmaceutics, food or cosmetic. Upon their chelation with transition metals such as Fe(II), the Fenton reaction catalysed by Fe(II) is inhibited. Hence, the production of Reactive Oxygen Species (ROS) is limited. Some illnesses are related to this oxidative stress, in particular inflammatory bowel diseases, with iron anemia complication. The screening and purification of metal-chelating peptides for their antioxidant properties is a federative project for the Universite de Lorraine. Two original screening methods of metal-chelating peptides are currently developed. The first method uses Surface Plasmon Resonance to screen complex mixtures of peptides and to selectively detect the most interesting ones for metal chelating properties. Besides, this method is of high interest for the prediction of separation in immobilized metal ion affinity chromatography. The second method, based on IMAC coupled to mass spectrometry, aims to quickly screen Fe(II) chelating peptides in complex mixtures of peptides - before starting the separation. Then, the identified iron-chelating peptides could be studied for their antioxidant properties for health applications, among them treatment of ferriprive anemia, or Inversely, hematochromatosis. Such metal chelating peptides could be anchored on nanoparticles either for bioimaging or therapeutic applications.