Biotin-PEG8-amine 是一种生物素标记的 PROTAC linker，属于 PEG 类。可用于合成 PROTAC 分子。 Biotin-PEG8-amine is PEG derivative containing a biotin group and a terminal primary amine group. The amine group can be coupled to carboxyl groups or 5'phosphate groups to form stable amide bonds. The hydrophilic PEG spacer increases solubility in aqueous media of the molecules conjugated to the biotin compound. It also helps to minimize steric hindrance involved with the binding to avidin molecules.