Tetrameric form of Protein

Streptavidin is known to be a common tetrameric protein that tightly binds to biotin, and considered as one of the smallest molecules. The valued constant binding for such interaction is high; it has made the biotin and streptavidin system to be the main focus of a variety of scientific studies meant to determine specific intermolecular interactions. This consequently gives full rise to any tight binding. If such strong binding may be fully understood, it can actually help in the probing of other systems wherein same interactions are significant.

Particularly, the current designs of brand-new medications, as well as ligands meant for nucleic acids and proteins benefit from possessing an understanding of involved interactions. With the assistance of Pat Stayton from Bioengineering Company, concerned molecular scientists use a combination of mutagenic methods and techniques, variety of thermodynamic measurements, and most importantly, crystallography. Such methods systematically change involved amino acids in the biotin binding process to help determine their general effects during the binding proper. Isolde Le Trong, together with Stefanie Freitag, carry out the crystallographic refining processes and analyses of various complexes of biotin analogs and streptavidin mutants.

The crystal streptavidin structure, when it was combined with biotin was first solved during 1989 by molecular scientist Hendrickson. Consequently, better solution to the issue was developed after almost twenty years, with over 134 structures which were positioned in the Protein Databank. The C – N termini of the residue protein were combined to give a small core streptavidin, which comprised of residues from 13 to 139. Likewise, the deletion of the termini is necessary for the high-level binding process of biotin. On the other hand, secondary structure of streptavidin-based monomer is formed out of 8 anti-parallel β-strands. They actually fold to offer an anti-parallel third-level structure of beta barrel. Currently, a lot of scientists believe that high-level binding processes done to cell forms, the two of the most common of which are melanomas and platelets, are actually caused by integrin-binding that occurs through any streptavidin RYD sequence.

One of the most obvious uses of streptavidin’s is its detection and cleansing of a great variety of known biomolecules. The stable bond that involves streptavidin and biotin can be utilized in the attachment of a number of biomolecules among one another or in a solid support. Harshest forms of the most ordinary conditions are needed to break the interaction between streptavidin and biotin. This biomolecular process denatures the molecular protein that must be cleansed and purified.

Of late, it has been found out that short-term streptavidin incubation using water, which possesses a temperature of more than 70 degrees Celsius will break any ongoing interaction without denaturing streptavidin. Such action allows for the re-using of any available stabilized support to the substance. Such application on streptavidin is known in the field as Strep-tag. This application involves a method that is optimized to easily detect and purify certain numbers of proteins. Streptavidin is also utilized in the conjugation of assays and blotting to a variety of existing molecules, such as the more popular horseradish peroxidase.