Avidin

WikiDoc Resources for Avidin

Articles

Most recent articles on Avidin

Most cited articles on Avidin

Review articles on Avidin

Articles on Avidin in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Avidin

Images of Avidin

Photos of Avidin

Podcasts & MP3s on Avidin

Videos on Avidin

Evidence Based Medicine

Cochrane Collaboration on Avidin

Bandolier on Avidin

TRIP on Avidin

Clinical Trials

Ongoing Trials on Avidin at Clinical Trials.gov

Trial results on Avidin

Clinical Trials on Avidin at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Avidin

NICE Guidance on Avidin

NHS PRODIGY Guidance

FDA on Avidin

CDC on Avidin

Books

Books on Avidin

News

Avidin in the news

Be alerted to news on Avidin

News trends on Avidin

Commentary

Blogs on Avidin

Definitions

Definitions of Avidin

Patient Resources / Community

Patient resources on Avidin

Discussion groups on Avidin

Patient Handouts on Avidin

Directions to Hospitals Treating Avidin

Risk calculators and risk factors for Avidin

Healthcare Provider Resources

Symptoms of Avidin

Causes & Risk Factors for Avidin

Diagnostic studies for Avidin

Treatment of Avidin

Continuing Medical Education (CME)

CME Programs on Avidin

International

Avidin en Espanol

Avidin en Francais

Business

Avidin in the Marketplace

Patents on Avidin

Experimental / Informatics

List of terms related to Avidin

## Contents

* 1 Overview
* 2 Relationship between avidin and biotin
* 3 References
* 4 External links

## Overview

[edit | edit source]

Avidin is a glycoprotein found in the egg white and tissues of birds, reptiles and amphibians. It contains four identical subunits having a combined mass of 67,000-68,000 daltons. Each subunit consists of 128 amino acids and binds one molecule of biotin. The extent of glycosylation is very high. Carbohydrate accounts for about 10% of the total mass of avidin. Avidin has a basic isoelectric point (pI) of 10-10.5 and is stable over a wide range of pH and temperature. Extensive chemical modification has little effect on the activity of avidin, making it especially useful for protein purification. Because of its carbohydrate content and basic pI, avidin has relatively high nonspecific binding.

## Relationship between avidin and biotin

[edit | edit source]

Avidin has a very strong affinity for biotin with a KD (dissociation constant) of approximately 10-15 M-1[1], the highest known affinity between any protein and its ligand, and, as such, prevents biotin absorption in the gastrointestinal tract. In biochemical applications, streptavidin or NeutrAvidin, which also bind very tightly to Biotin, are often used in place of avidin.

Avidin's affinity for biotin is exploited in wide ranging biochemical assays, including western blot, ELISA, ELISPOT and pull-down assays. Avidin immobilized onto solid supports is also used as purification media to capture biotin-labelled protein or nucleic acid molecules. For example, cell surface proteins can be specifically labelled with membrane impermeable biotin reagent, then specifically captured using an avidin-based support.

## References

[edit | edit source]

1. ^ Bayer, Ed: "The Avidin-Biotin Complex", Dept. of Biological Chemistry, Weizmann Institute of Science, Israel

## External links

[edit | edit source]

* Avidin at the US National Library of Medicine Medical Subject Headings (MeSH)

* v
* t
* e

Proteins: Globular proteins

Serum globulins|

| Alpha globulins|

| serpins:|

* alpha-1 (Alpha 1-antichymotrypsin, Alpha 1-antitrypsin)
* alpha-2 (Alpha 2-antiplasmin)
* Antithrombin (Heparin cofactor II)

|

carrier proteins:|

* alpha-1 (Transcortin)
* alpha-2 (Ceruloplasmin)
* Retinol binding protein

other:|

* alpha-1 (Orosomucoid)
* alpha-2 (alpha-2-Macroglobulin, Haptoglobin)

Beta globulins|

| carrier proteins:|

* Sex hormone-binding globulin
* Transferrin

|

other:|

* Angiostatin
* Hemopexin
* Beta-2 microglobulin
* Factor H
* Plasminogen
* Properdin

Gamma globulin|

* Immunoglobulins

Other|

* Fibronectin (fFN: Fetal fibronectin)
* Macroglobulin/Microglobulin
* Transcobalamin
* Edestin

Other globulins|

* Beta-lactoglobulin
* Lactoferrin
* Thyroglobulin
* Alpha-lactalbumin
* 11S globulin family (seeds)
* 7S globulin family (seeds)

Albumins|

| Egg white|

* Conalbumin
* Ovalbumin
* Avidin

|

Serum albumin|

* Human serum albumin
* Bovine serum albumin
* Prealbumin

Other|

* C-reactive protein
* Lactalbumin (Alpha-lactalbumin)
* Parvalbumin
* Ricin

* see also disorders of globin and globulin proteins

* v
* t
* e

Protein, glycoconjugate: glycoproteins and glycopeptides

Mucoproteins|

| Mucin|

* CD43
* CD164
* MUC1
* MUC2
* MUC3A
* MUC3B
* MUC4
* MUC5AC
* MUC5B
* MUC6
* MUC7
* MUC8
* MUC12
* MUC13
* MUC15
* MUC16
* MUC17
* MUC19
* MUC20

|

Other|

* Haptoglobin
* Intrinsic factor
* Orosomucoid
* Peptidoglycan
* Phytohaemagglutinin
* Ovomucin

Proteoglycans|

| CS/DS|

* Decorin
* Biglycan
* Versican

|

HS/CS|

* Testican
* Perlecan

CS|

* Chondroitin sulfate proteoglycans: Aggrecan
* Neurocan
* Brevican
* CD44
* CSPG4
* CSPG5
* Platelet factor 4
* Structural maintenance of chromosomes 3

KS|

* Fibromodulin
* Lumican
* Keratocan

HS|

* Syndecan 1

Other|

* Activin and inhibin
* ADAM
* Alpha 1-antichymotrypsin
* Apolipoprotein H
* CD70
* Asialoglycoprotein
* Avidin
* B-cell activating factor
* 4-1BB ligand
* Cholesterylester transfer protein
* Clusterin
* Colony-stimulating factor
* Hemopexin
* Lactoferrin
* Membrane glycoproteins
* Myelin protein zero
* Osteonectin
* Protein C
* Protein S
* Serum amyloid P component
* Sialoglycoprotein
* CD43
* Glycophorin
* Glycophorin C
* Thrombopoietin
* Thyroglobulin
* Thyroxine-binding proteins
* Transcortin
* Tumor necrosis factor alpha
* Uteroglobin
* Vitronectin

de:Avidin fi:Avidiini

Template:WH

Template:WS
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template