PEG TFP Ester

PEG TFP ester is categorized as an amine-reactive PEG reagent, featuring a 2,3,5,6-tetrafluorophenol (TFP) functional group attached to one end of the PEG chain. It serves as an alternative to NHS esters, renowned for their lesser stability and increased susceptibility to hydrolysis in water when compared to TFP esters. NHS esters stand as the most commonly utilized amine-reactive acylating agents, yet TFP esters exhibit superior reactivity and stability.

In aqueous media, the optimal pH for conjugating TFP esters to amines surpasses that of NHS esters, with TFP esters favoring a range greater than 7.5, compared to the 7.0-7.2 range for NHS esters. However, it's noteworthy that TFP ester reagents exhibit lower water solubility than their NHS ester counterparts due to the hydrophobic nature of the TFP group on the PEG chain. This challenge can be addressed by employing water and water-miscible organic solvents, such as DMac or acetonitrile, to facilitate the reaction. In situations where organic solvents are restricted, NHS esters may be deemed more suitable than TFP esters.

Biotin-PEG-TFP Ester

DOTA-tris(t-Bu)-Amido-PEG-NHS Ester

DOTAGA-PEG-TFP Ester