HydraLinkTM conjugation chemistry is based on the reaction of a HyNic linker with a 4FB linker to form a stable bis-aryl hydrazone bond. The bond created is both stable and UV-traceable. This unique covalent bond is created when hydrazinonicotinamide (HyNic), incorporated into one type of biomolecule reacts with a formylbenzamide linker (4FB), incorporated into a second biomolecule. This type of hydrazone bond formed is the only known example of a stable Schiff base, which requires no additional steps (reduction) to stabilize the bond.
S-HyNic and S-4FB were designed and engineered to be ‘complementary’ and thus they react only with each other. S-HyNic was developed to incorporate 6-hydrazinonicotinamide groups into amine-containing biomolecules via an activated N-hydroxysuccinimide ester. This linker possesses a nucleophilic, aromatic hydrazine moiety that is protected as its alkyl (acetone) hydrazone. S-4FB (succinimidyl 4-formylbenzoate) is the other linker forming the basis of our HydraLink technology. S-4FB is an aromatic aldehyde that was developed to incorporate 4-formylbenzamide groups into amine-containing biomolecules via an activated N-hydroxysuccinimide ester.
Only aromatic aldehydes form permanently stable covalent hydrazone bonds with aromatic hydrazines or aromatic hydrazides. Aliphatic hydrazines or hydrazides (sold by other vendors) do not form stable and permanent covalent bonds when they react with aliphatic and/or aromatic aldehydes. Only SoluLink’s proprietary HydraLink chemistry based on reaction of two aromatic functionalities (HyNic and 4FB) can form a permanent resonance stabilized covalent bond.
