ovavidin

Ovavidin is a biotin-binding protein found in the eggs of birds. It is described as the avian homolog of avidin and is secreted by the oviduct into the developing egg, where it is present in the egg white. Like avidin, ovavidin binds biotin with high affinity and specificity and can form complexes with biotinylated molecules.

Structurally, ovavidin is a tetrameric glycoprotein, with four biotin-binding sites per functional unit. Each subunit contributes to a surrounding binding pocket, and the tetrameric assembly confers strong binding to biotin. The subunits are typically small proteins, and the overall complex is relatively large when considered as a single molecule. Ovavidin is generally characterized by a high isoelectric point and substantial resistance to moderate heat, although exact properties can vary among bird species due to differences in glycosylation.

In practice, ovavidin is less widely used than avidin or streptavidin in biotechnology, but it has been investigated as an alternative affinity reagent. Applications reported in the literature include biotin-based detection, affinity capture of biotinylated probes, and studies of egg proteins. Differences in binding kinetics, stability, and glycosylation can influence performance relative to other biotin-binding proteins.

Distribution and abundance of ovavidin vary among avian species, reflecting evolutionary differences in egg proteins. It is primarily associated with the avian oviduct and egg white, where it contributes to the repertoire of egg-yolk and egg-white proteins that interact with biotin-containing compounds.