Amine-PEG-NTA

Amine-PEG-NTA a heterobifunctional polyethylene glycol (PEG) linker featuring a primary amine group at one terminus and a nitrilotriacetic acid (NTA) group at the other. It is designed for the oriented immobilization or labeling of recombinant proteins containing a polyhistidine (His-tag) sequence. The primary amine enables covalent conjugation to carboxyl groups on surfaces, nanoparticles, or biomolecules via carbodiimide chemistry (e.g., EDC/NHS), while the NTA moiety, when charged with divalent metal ions (typically Ni²⁺ or Co²⁺), provides high-affinity, reversible binding to His-tagged proteins through metal coordination. The PEG spacer enhances water solubility, reduces non-specific binding, and offers steric flexibility. This reagent is widely used in biosensor development, protein microarray fabrication, nanoparticle functionalization, and the construction of oriented protein conjugates where controlled orientation via the His-tag is required.