Bis-PEG17-NHS ester

This Bis-PEG17-NHS ester is a bifunctional, PEG-based linker designed for efficient conjugation of two biomolecular partners in targeted protein degradation workflows. Its NHS-ester termini enable selective acylation of primary amines, supporting modular assembly of PROTAC constructs with improved solubility and linker flexibility. The two reactive ends facilitate controlled stoichiometry and spatial presentation of ligands, and the following sections describe its structure and practical reactivity considerations in detail.

Structure: The linker comprises a PEG scaffold bearing two N-hydroxysuccinimide ester groups at the termini. It contains ester and ether linkages typical of PEG architectures, with an amide-forming acyl functionality. The extended, flexible polyether chain imparts high aqueous compatibility and conformational adaptability.

Reactivity: NHS esters react with primary amines via nucleophilic acyl substitution to form stable amide bonds while releasing N-hydroxysuccinimide. For PROTAC assembly, use amine-containing ligands under mildly basic conditions in anhydrous or low-water organic/aqueous buffers compatible with NHS stability. Avoid strong nucleophiles and prolonged exposure to water, and consider sequential coupling to control bis-conjugation efficiency.