What does avidin mean?
Avidin is a protein found naturally in egg white, best known for its extraordinarily tight grip on biotin, also called vitamin B7. The bond between the two is among the strongest non-covalent interactions known in biology, which gives avidin its practical importance: biochemists exploit it in laboratory techniques such as ELISA assays and affinity purification, where anything tagged with biotin can be captured using avidin. Its name reflects this behavior — it comes from the Latin 'avidus,' meaning greedy or eager, because the protein seizes biotin so readily. In nutrition, avidin matters for a different reason: consuming large amounts of raw egg white can bind dietary biotin and lead to deficiency, though cooking denatures the protein and eliminates the problem. Related bacterial proteins such as streptavidin serve similar laboratory roles. Outside scientific contexts, the word rarely appears, but within biochemistry it is a staple term.
nounA glycoprotein found in egg white that binds biotin (vitamin B7) extremely tightly, making raw egg white capable of causing biotin deficiency if consumed in large quantities.
- A tetrameric glycoprotein in egg white that binds biotin with extremely high affinity, used widely in biochemical assays.
"The researchers exploited the strong bond between avidin and biotin to attach enzymes to cell surfaces."
"The avidin–biotin interaction is one of the strongest non-covalent bonds known in biology."
"Because avidin in raw egg white blocks biotin absorption, cooking eggs largely deactivates it."
Rarely used; 'avidin' is normally an uncountable mass noun. The plural appears only when referring to multiple distinct avidin-type proteins or species variants.
"Avidins isolated from different bird species vary slightly in their biotin-binding strength."
Egg white contains a protein so greedy for biotin that eating raw egg whites daily can actually cause a vitamin deficiency — which is exactly how it got its name, from the Latin for 'greedy.'
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of avidin
Avidin was named in the mid-20th century after research showed that egg white contained a factor that caused 'egg-white injury' — a biotin deficiency observed in animals fed raw egg whites. The name combines the Latin adjective 'avidus' (greedy, eager), from the verb 'avēre' (to crave), with the suffix '-in' conventionally used for proteins. English words sharing this root include 'avid' and 'avidity.' The protein was first isolated and characterized in the 1940s.
How avidin is actually used
Avidin is a technical term used almost exclusively in biochemistry, molecular biology, and nutrition science. It is an uncountable mass noun when referring to the substance generally, though 'avidins' occasionally appears when distinguishing variants across species. It carries no figurative or informal usage.
Easily confused with avidin
Streptavidin is a similar biotin-binding protein produced by the bacterium Streptomyces avidinii, whereas avidin is the natural protein found in egg white.
Avid is an adjective meaning eager or enthusiastic, while avidin is a specific protein in egg white; both share the same Latin root.