Avidin: Difference between revisions
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Avidin is one of the [[CBI Molecules]] being studied in the [http://www.umass.edu/cbi/ University of Massachusetts Amherst Chemistry-Biology Interface Program] at UMass Amherst and on display at the [http://www.molecularplayground.org/ Molecular Playground]. | Avidin is one of the [[CBI Molecules]] being studied in the [http://www.umass.edu/cbi/ University of Massachusetts Amherst Chemistry-Biology Interface Program] at UMass Amherst and on display at the [http://www.molecularplayground.org/ Molecular Playground]. | ||
Avidin is a tetrameric protein what in different words means that if we could, we would see a protein with four regions that look identical one to the other. However, to isolate the four regions as a whole in order to show the protein three dimensional structure has been quite diffucult so far and we just can see the three dimensional structure for two of those four units. <ref group="xtra">PMID:8506353</ref><ref group="xtra">PMID:8344421</ref> | <scene name='41/410356/Cv/5'>Avidin is a tetrameric protein</scene> what in different words means that if we could, we would see a protein with four regions that look identical one to the other. However, to isolate the four regions as a whole in order to show the protein three dimensional structure has been quite diffucult so far and we just can see the three dimensional structure for two of those four units. <ref group="xtra">PMID:8506353</ref><ref group="xtra">PMID:8344421</ref> | ||
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Revision as of 15:01, 12 January 2016
Avidin (Av) is a protein found in egg white which binds biotin (vitamin B7) with high affinity. This property makes it a powerful tool in various protein pull-down assays. Similar proteins are:
Avidin is one of the CBI Molecules being studied in the University of Massachusetts Amherst Chemistry-Biology Interface Program at UMass Amherst and on display at the Molecular Playground. what in different words means that if we could, we would see a protein with four regions that look identical one to the other. However, to isolate the four regions as a whole in order to show the protein three dimensional structure has been quite diffucult so far and we just can see the three dimensional structure for two of those four units. [xtra 1][xtra 2] The binding affinity of biotin for the avidin is very hight or in other words, the strength of the interations between the biotin and the avidin receptors is so strong that washing the biotin-avidin complex is not enough to remove the ligand from its pocket. This is not even possible by adding more biotin molecules to the system avidin-biotin. Once a biotin has bound a pocket in the avidin, it is almost imposible to remove it in a biologica system! Each monomer is an eight-stranded antiparallel . Binding of biotin involves a highly stabilized network of polar and hydrophobic interactions. The presence of additional hydrophobic and hydrophilic groups in the binding site of avidin may account for its higher affinity constant. Unexpectedly, a residual N-acetylglucosamine moiety was detected in the deglycosylated avidin monomer. These appear along with the biotin but outside of the biotin binding pockets. See also: About this Structure2avi is a 2 chains structure of sequences from Gallus gallus. Full crystallographic information is available from OCA. |
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3D structures of Avidin3D structures of Avidin
Updated on 12-January-2016
ReferenceReference
- ↑ Livnah O, Bayer EA, Wilchek M, Sussman JL. Three-dimensional structures of avidin and the avidin-biotin complex. Proc Natl Acad Sci U S A. 1993 Jun 1;90(11):5076-80. PMID:8506353
- ↑ Livnah O, Bayer EA, Wilchek M, Sussman JL. The structure of the complex between avidin and the dye, 2-(4'-hydroxyazobenzene) benzoic acid (HABA). FEBS Lett. 1993 Aug 9;328(1-2):165-8. PMID:8344421