I. Product Overview
Bromo-PEG-Amino tert-Butyl Ester is a multifunctional, dual-functional PEG linker composed of a bromo terminus, an adjustable-length polyethylene glycol (PEG) chain, and an amino tert-butyl ester protecting group. This compound holds significant value in bioconjugation chemistry and drug development, playing a key role particularly in the emerging field of PROTAC technology.

II. Structural Features

• Bromo terminus: Acts as an electrophile, reacting with nucleophiles such as thiols and amines for efficient conjugation.

• Amino tert-butyl ester protecting group: Can be deprotected under acidic conditions to release a free amino group for subsequent functionalization.

• Adjustable PEG chain length:

  • Number of PEG units: Customizable based on requirements.

  • Chain length effects: Solubility, steric hindrance, pharmacokinetic properties.

• Excellent physicochemical properties:

  • Good solubility in both aqueous and organic solvents.

  • Enhances biocompatibility of conjugated products.

  • Reduces non-specific interactions.

III. Major Application Areas

• PROTAC Development

  • Linker role: Serves as a connecting bridge between the E3 ligand and the target protein ligand.

  • Optimization properties:

    • Modulates cell permeability of PROTAC molecules.

    • Affects the formation efficiency of the ternary complex.

    • Regulates degradation activity and selectivity.

  • Structural advantages:

    • Bromo end for attaching the E3 ligand.

    • Deprotected amino end for attaching the target protein ligand.

    • PEG chain provides necessary flexibility.

• Bioconjugation Chemistry

  • Functionalization of proteins/antibodies.

  • Modification of peptide compounds.

  • Attachment of fluorescent labels.

• Materials Science

  • Polymer functionalization.

  • Surface modification.

  • Nanomaterial functionalization.

• Drug Delivery Systems

  • Prodrug design.

  • Drug-carrier conjugation.

  • Improving drug solubility and stability.

IV. Detailed Description for PROTAC Applications

• Design Advantages

  • Modular construction: The bromo and amino groups provide distinct conjugation points, facilitating modular assembly of PROTACs.

  • Adjustable length: The selection of 1-12 PEG units allows fine-tuning of the linker length to optimize degradation efficiency.

  • Protecting group strategy: The tert-butyl ester protection ensures the amino group remains stable during synthesis and can be selectively deprotected when needed.

• Performance Implications

  • Short-chain PEG (1-4 units): Higher rigidity, suitable for targets requiring precise spatial positioning.

  • Medium-chain PEG (5-9 units): Balances flexibility and spatial constraint, suitable for most PROTAC designs.

  • Long-chain PEG (10-12 units): Maximum flexibility, suitable for targets requiring extensive spatial exploration.