Isolation, Purification and Characterization of Avidin from Egg White

Student: Bukola Teniola Obisesan (Project, 2025)
Department of Biochemistry
Usmanu Danfodio University, Sokoto, Sokoto State

Abstract

Avidin, a glycoprotein found in egg white has numerous applications in biochemistry, which also has high-affinity to biotin-binding protein, comprises of four identical subunits with a molecular weight of approximately 66-70 kDa. Avidin is an alkaline with an isoelectric point of 10.5, highly stable, homotetrameric protein was isolated and purified from egg white using a combination of Ammonium sulfate salt precipitation, DEAE ion exchange chromatography, and gel filtration. The purified Avidin was characterized using Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis SDS-PAGE. The results showed that the purified Avidin had a molecular weight of approximately 68kDa and exhibited high affinity for biotin. The purification protocol yielded a high recovery of Avidin with a purity of >95%. The isolated Avidin was found to be thermostable up to 85°C and resistant to proteolytic degradation. This study demonstrates an efficient method for the isolation, purification, and characterization of Avidin from egg white, which can be useful for various biotechnological and biomedical applications.

Keywords
isolation purification characterization avidin egg-white DEAE Sephadex Chromatography Gel Electrophoresis
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