Biotin azido derivative

Figure 17.21 An azido-farnesyl diphosphate derivative can be added to cells to obtain farnesylated proteins containing terminal azide groups that can be targeted in a Staudinger ligation reaction. Biotinylation of these post-translationally modified proteins can be done in vivo using a biotin-phosphine derivative.

PEG-methacrylate was selected as the monomer to ensure biocompatibility, as PEGylated surfaces are known to inhibit protein binding. To demonstrate the accessibility of the surface azide groups, an azido-derivative of biotin was clicked to the polymer-brush-modified surface subsequently, surface plasmon resonance (SPR) was used to confirm the selective binding with streptavidin in preference to other proteins. 

Add to the washed cells 60 pi of a 5 mM concentration of the phosphine derivative to couple to the azido-sugar groups on the cell surface (e.g., biotin-PEG-phosphine). 

Figure 17.19 An azido-sialic acid derivative that gets incorporated into glycans in cells can be labeled specifically with a biotin-phosphine tag using the Staudinger ligation process. The result is an amide bond linkage with the glycan.

A chemoenzymatic synthesis of the P-a-methyl 2 -deoxynucleoside triphosphates 122 has been described which involves reaction of the 5 -0-(methylpho-sphonyl)-N-protected nucleosides with pyrophosphate in the presence of CDI. Removal of the base protection by treatment with penicillin amidase gave compounds 122 leaving the labile a-methylphosphonate intact. A number of 2 -deoxythymidine 5 -triphosphate and 3 -azido-2, 3 -dideoxythymidine 5 -tripho-sphate analogues (123) containing a hydrophobic phosphonate group have also been synthesised and evaluated as substrates for several viral and mammalian polymerases. Some y-ester (124) and y-amide (125) derivatives of dTTP and 3 -azido-2, 3 -dideoxythymidine 5 -triphosphate (AZTTP) were also synthesized and studied. The y-phenylphosphonate triphosphate 126 and its conjugation to biotin and fluorescein labels has also been described. 

Forster et al. (1985) synthesized a derivative of biotin containing a photoactivable azido group. This product is commercially available... 

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