Avidin binding

Miller RT, Kubier P (1997) Blocking of endogenous avidin binding activity in immunohistochem istry the use of egg whites. Appl Immunohistochem 5 63 66... 

POLARIS Chromagen Reactive biotinylated linker covalently binds phosphorylated peptide, producing FP signal change after avidin binding... 

Kaasgaard T, Mouritsen O, Jorgensen K. Screening effect of PEG on avidin binding to liposome surface receptors. Int J Pharm 2001 214 63. 

Many biotinylated succinimide esters are now available. Most of these variations alter the size of the spacer arm between the succinimide coupling group and the biotin. The additional spacers could facilitate avidin binding and, thus, may be critical for some applications (9). 

There are certain specimen preparations that create problems for some of the sandwich methods. Frozen or fresh cell preparations may have inherent avidin-binding properties, as some fixed preparations can have. While this should not preclude the use of these methods, one should be aware of the potential limitations and have alternate methodologies available for confirmatory testing. 

This method, either standard or elite (increased molar ratio), remains the forefront of much of the immunocytochemistry being performed today, and will be the main subject of this chapter. There are new methods, though, that are being used with increased frequency, such as the labeled-avidin binding method, sometimes called the streptavidin-binding method, and a newer catalyzed amplification method that uses avidin, biotin, peroxidase, and a biotinyl tyramide to achieve even more sensitivity. These methods will be discussed at the end of this chapter. 

Rodriguez-Soto, J., Wamke, R., and Rouse, R. (1997) Endogenous avidin-bind-ing activity in paraffin-embedded tissue revealed after microwave treatment. Appl. Immunohistochem. 5, 59-62. 

The basic methods to quantify biotin in food are bioassays, avidin-binding assays or fluorescent derivative assays. Although the avidin-binding assay of biotin and its metabolites after the separation by HPLC is considered as one of the best cnrrently available methods [587], it is still not largely diffnsed. 

In the avidin-biotin (ABC) method a complex of avidin and biotinylated tracer containing the free avidin binding sites is applied to the biotinylated antibody. As a high... 

Sections (5 xm thick) of formalin-fixed and paraffin-embedded tissues are placed on slides, dried overnight at 37°C, deparaffinized with xylene, and rehydrated with descending concentrations of ethanol. They are treated with 3% hydrogen peroxide in methanol for 5-10 min and then rinsed with PBS. The slides are immersed in 10 mM citrate buffer (pH 6.0), and heated for 2 min at 100% power, followed by 8 min at 80% power. After being rinsed in PBS, the sections are incubated in an appropriate primary antibody. They are rinsed in PBS and then treated for 4-8 min with egg white avidin solution (2.5 g of egg white avidin in 0.1 mM PBS) (Ventana Medical Systems). Avidin binds to endogenous biotin. 

Figure 4. Avidin-biotin-complex (ABC) binding to mast cells in submucosa (a) before, and (b) after blocking for endogenous avidin binding activity (EABA).

Wood G, et al. Suppression of Endogenous Avidin-Binding Activity in Tissues and Its Relevance to Biotin-Avidin Detection Systems. Journal of Histochemistry and Cytochemistry 2981 29 1196-204. 

Table 1 Useful strept(avidin) derivatives. Streptavidin derivatives are reviewed in [27] and [28], and avidin derivatives are reviewed in [30], Besides the review articles, some specific references are listed. Note that this list does not include chimeric protein complexes formed from strept(avidin) binding of biotinylated protein...

The original interest in avidin was because of the egg white injury that was subsequently shown to be avidin-induced biotin deficiency. Thereafter, avidin was used because of its high affinity for biotin (a dissociation constant of 10 mol per L), not only to induce experimental biotin deficiency, but also to bind to biotin in isolated enzymes and thus, by irreversible inhibition, demonstrate the coenzyme role of biotin. Because of the stability of the avidin-biotin complex, it has not been possible to use immobilized avidin as a means of purifying biotin enzymes - there seems to be no way in which the enzyme can be released from avidin binding. Because of its high affinity for biotin, avidin is used to provide an extremely sensitive system for linking reporter molecules in a variety of analytical systems. 

Both avidin and the avidin-biotin complex are very stable to heat. To release biotin from avidin binding, autoclaving above 130°C is required, and free avidin is stable up to about 85°C. Avidin is also resistant to proteolysis and, as is obvious from the use of raw egg white diets to induce biotin deficiency, biotin cannot be released from avidin binding in the gastrointestinal tract. Lysosomal hydrolases do release biotin from avidin binding, and intravenously administered avidin-biotin can be a source of biotin. 

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