Aladdin™ Sulfo-NHS-LC-Desthiobiotin

Product introduction:Sulfo-NHS-LC-Desthiobiotin is a long-chain, amine-reactive labeling reagent whose biotin-like group is elutable from streptavidin, making it ideal for purified or cell surface protein labeling and purification.Features of EZ-Link Sulfo-NHS-LC-Desthiobiotin:• :Desthiobiotin:—analog of biotin allows easy elution from streptavidin, an ideal feature for affinity purification applications:• :Protein labeling:—tag antibodies or proteins in purified or mixed samples to enable high recovery in pull-down assays with streptavidin beads:• :Cell surface labeling:—modifies only surface proteins of whole cells because the negatively charged reagent does not permeate cell membranes:• :Amine-reactive:—reacts with primary amines (-NH2), such as lysine side-chains, or the amino-termini of polypeptides:• :Soluble:—charged sulfo-NHS group increases reagent water solubility compared to ordinary NHS-ester compounds:Sulfo-NHS-LC-Desthiobiotin is a variant of biotin that is activated as a sulfo-NHS ester with a long-chain (LC) spacer arm to covalently label primary amines (-NH2) of proteins or other molecules with desthiobiotin groups. The desthiobiotin tag binds to streptavidin and other biotin-binding proteins with high specificity yet readily elutes with mild conditions (i.e., by competitive displacement with regular, free biotin). As such, this reagent is a useful alternative toDesthiobiotin is a single-ring, sulfur-free analog of biotin that binds to streptavidin with nearly equal specificity but less affinity than biotin (1/Kd = 10:11: vs. 10:15: M, respectively). Consequently, desthiobiotinylated bait proteins and their interacting partners can be eluted readily and specifically from streptavidin affinity resin using mild conditions based on competitive displacement with free biotin. For pull-down assay experiments with biological samples, this soft-release characteristic of desthiobiotin also helps to minimize co-purification of endogenous biotinylated molecules, which remain bound to streptavidin upon elution of the target protein complexes with free biotin. The modified avidin-biotin affinity system also eliminates the need to use harsh elution conditions that might disassociate complexes and/or damage the target protein or cell. Desthiobiotin-based techniques are ideal when using native or recombinant proteins that are not expressed with a fusion tag and when isolating captured proteins under native conditions, such as targeting intact cells or cell surface proteins.Labeling with NHS Ester Reagents:N:-Hydroxysulfosuccinimide (NHS) esters of biotin are the most popular type of biotinylation reagent. NHS-activated biotins react efficiently with primary amino groups (-NH2) in alkaline buffers to form stable amide bonds. Proteins typically have several primary amines that are available as targets for labeling, including the side chain of lysine (K) residues and the N-terminus of each polypeptide. Most sulfo-NHS esters are directly water soluble but not membrane permeable. Plain NHS esters are less soluble in aqueous buffers but are membrane permeable.• :Spacer:Short, 17.3 Å :• :Labeling Method:Chemical Labeling :• :Cell Permeability:Cell-Impermeant.