Multifunctional peptides from egg white lysozyme

Hen's egg white lysozyme (HEWL) is one of the major egg white proteins with well demonstrated antimicrobial activity. Bioactive peptides other than antimicrobial peptides from HEWL have not been reported; therefore, the purpose of the study was to explore new bioactivities of lysozyme-derived bioactive peptides. HEWL was hydrolysed with Alcalase and fractionated by cation-exchange chromatography. The Alcalase HEWL hydrolysate and its fractions were analyzed for inhibitory activities against calmodulin-dependent phosphodiesterase (CaMPDE) and antioxidant activities using oxygen radical absorbance capacity-fluorescein (ORAC-FL), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation (ABTS(center dot+)) and 2.2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) radical scavenging methods. The fractionated peptides had higher CaMPDE inhibition activity, ORAC-FL value and ABTS(center dot+) scavenging activity than those of the hydrolysate. Peptide sequences in the most overall active fractions were characterized by LC-MS/MS. Our results showed that HEWL hydrolysate and its peptide fractions may serve as useful ingredients in the formulation of functional foods and nutraceuticals. (C) 2009 Elsevier Ltd. All rights reserved.