Characterization of zinc-chelating peptides prepared from Arthrospira platensis proteins

Abstract

This research investigates the efficacy of proteins derived from Arthrospira platensis (A. platensis) as biological zinc enhancers through the formation of peptide-zinc chelates, with the objective of improving zinc efficiency in therapeutic food applications. Enzymatic hydrolysis was performed using alcalase and flavourzyme to enhance protein functionality, achieving a protein purity of 97.50 ± 2.00% and a degree of hydrolysis of 30.42 ± 1.35% under optimal conditions (50 °C, pH 7.0). The resulting enzymatically produced protein hydrolysates (APH) demonstrated significant zinc-chelating properties, as well as improved antibacterial and antioxidant activities. Characterization of the APH-Zn complexes revealed distinct structural variations, with APH-Zn exhibiting a rougher morphology compared to APH. During simulated gastric digestion, APH-Zn maintained a solubility of 54.20%, which was significantly higher than the 10.3% solubility observed for zinc sulfate during intestinal digestion. The APH peptides effectively scavenged free radicals, achieving a 39.28 ± 0.89% inhibition at a concentration of 0.1 mg/ml. Moreover, the APH-Zn complex displayed superior cell viability (79.17 ± 0.03%) compared to zinc sulfate (13.69 ± 0.01%) at a concentration of 5 mg/ml. Additionally, the isolated peptides exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus (p < 0.05). The antibacterial mechanism of APH-Zn is attributed to its capacity to compromise the integrity of bacterial cell walls. These findings underscore the potential application of these peptides as functional components in zinc supplementation and their relevance in the food industry for enhancing both nutritional and health benefits.