Avidin Activity

Avidin acts as an antibacterial protein like other egg white proteins, such as Lysozyme and Conalbumin. However, what makes Avidin significant is its high affinity for Biotin.

The Avidin-Biotin interaction is the strongest non covalent, biological interaction (Kd = 10-15 M) between a protein and a ligand. One molecule of Avidin binds four molecules of Biotin. The bond formation between Biotin and Avidin is very rapid, and, once formed, is unaffected by wide extremes of pH, temperature, organic solvents, and other denaturing agents. The Avidin-Biotin complex is also resistant to enzymatic proteolysis.

This Avidin-Biotin binding system has been extensively applied in biotechnology and diagnostics, in particular to the fields of:

A \ Immunoassay
B \ Hystochemestry
C \ Cytochemistry
D \ Biotin purification
E \ Chromosome visualization
F \ Enzyme Linked ImmunoSorbent Assay (ELISA)

Besides its use in diagnostics, Avidin is now used in the Pharmacology field as an API.

Fordras S.A. has been a forerunner in developing the use of Avidin as a marker in the treatment of tumors. This revolutionary radioimmunology technique “which has showed virtually no toxicity, has successfully been applied to the treatment of a brain tumor called gliobastoma”.

http://www.ieo.it/inglese/innovazioni/av_biot.shtml