Isolation and Characterization of a Novel Chicken Egg White Protein with Scavenger Receptor Cysteine-rich Domains

Abstract

There are more than 70 proteins in chicken egg white, most of which have a role in host defense. We isolated a novel protein from chicken egg white which we termed EW135 by means of polyethylene glycol precipitation and ion-exchange chromatography, and an amino acid sequence analysis of its tryptic peptides showed it to be a member of the group B scavenger receptor cysteine-rich domain superfamily. EW135 was speculated to be complexed with a substance (s) in egg white in a Ca²⁺-dependent manner. From a structural point of view, EW135 may play a role in host defense.