Methylamino-PEG4-t-butyl ester linker containing tertiary amine group and two t-butyl ester groups. The N-methylamine substantiallly increase the aqueous solubility of the hydrophilic PEG spacer. The two t-butyl protected carboxyl acid groups can be deprotected under acidic conditions to form acid, which can undergo amide coupling and esterification with coupling reagents, such as EDC, DCC and HATU, etc.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.