EZ-Link™ Alkoxyamine-PEG4-Biotin

Thermo Scientific EZ-Link Alkoxyamine-PEG4-Biotin is a biotinylation reagent containing a four-unit polyethylene glycol (PEG) spacer for biotinylating macromolecules at carbohydrate groups that have been oxidized to form aldehydes.

Features of EZ-Link Alkoxyamine-PEG4-Biotin:

• Glycoprotein labeling—biotinylate glycosylated proteins at sialic acid residues for detection or purification using streptavidin probes or resins
• Cell surface labeling—biotinylate and isolate cell surface glycoproteins; reagent does not permeate membranes of whole cells
• Aldehyde-reactive—reacts with aldehydes formed by periodate-oxidation of sugar groups
• Alkoxyamine-activated—aminooxy group forms more stable linkages than hydrazide reagents
• Pegylated – spacer arm contains a hydrophilic, 4-unit, polyethylene glycol (PEG) group
• Enhances solubility – pegylation imparts water solubility to the biotinylated molecule, helping to prevent aggregation of biotinylated antibodies stored in solution
• Irreversible—forms stable (permanent) oxime bonds; spacer arm cannot be cleaved
• Solubility—usually dissolved in DMSO to make concentrated stock solution
• Medium length—spacer arm (total length added to target) is 27.0 angstroms, sufficient to minimize steric hindrance for binding

Aminooxy-biotin reagents such as this one are useful for biotinylating glycoproteins and other molecules that have oxidizable polysaccharides groups. The alkoxyamine group (also called an aminooxy or aminoxy group) conjugates to aldehydes of oxidized sugars. EZ-Link Alkoxyamine-PEG-Biotin reagents contain a multi-functional extended spacer arm that is a flexible, non-immunogenic hydrophilic polyethylene glycol (PEG), which imparts water solubility to labeled molecules. Consequently, antibodies labeled with pegylated biotin reagents exhibit less aggregation when stored in solution compared to antibodies labeled with reagents having only hydrocarbon spacers.

We manufacture biotin reagents to ensure the highest possible overall product integrity, consistency and performance for the intended research applications.

Biotinylation reagents differ in reactivity, length, solubility, cell permeability and cleavability. Hydrazides and alkoxyamines are two types of carbonyl-reactive groups. Alkoxyamines (—O-NH2) react specifically with aldehyde groups in near-neutral conditions to form stable oxime linkages. The reaction is more efficient in the presence of aniline (Part No. 88944). Alternatively, alkoxyamines can be conjugated to carboxylic acids using EDC carbodiimide chemistry.

Reactive aldehyde groups can be generated in glycoproteins and other polysaccharide compounds by oxidation of constituent sugar diols using sodium periodiate (Part No. 20504). Sialic acid residues are common components of protein glycosylation and are easily converted to aldehydes with 1 mM NaIO4.