tBuO-Ste-Glu(AEEA-AEEA-OSu)-OtBu

tBuO-Ste-Glu(AEEA-AEEA-OSu)-OtBu is a synthetic multifunctional building block designed for biomolecule modification, combining lipophilic and hydrophilic elements with a reactive conjugation site. It consists of a glutamic acid core where the alpha-amino group is linked to a stearic acid (Ste) moiety with a tert-butyl ester (tBuO) protecting group, one glutamic acid carboxyl is also tert-butyl protected (OtBu), and the other carboxyl group is connected through two AEEA (PEG-like) units ending in an N-hydroxysuccinimide (NHS, OSu) ester for conjugation to primary amines.

Appearance

• White to off-white solid, potentially waxy due to the stearic acid chain.

Source

• Chemically synthesized; not naturally occurring.
• Available from specialized bioconjugation and lipid chemistry suppliers.

Molecular Weight and Structure

• Approximate molecular weight: 939.2 g/mol (C47H82N4O14).
• Structure includes stearic acid with tert-butyl protection, glutamic acid core, two PEG-like AEEA units forming a hydrophilic spacer, and terminal NHS ester.

Biological Activity

• Generally biologically inert alone; activity depends on conjugated molecules.
• Stearic acid provides membrane anchoring; AEEA spacer enhances solubility and reduces steric hindrance.
• NHS ester enables efficient conjugation to primary amines.

Purity and Microbial Contamination

• Typically ≥ 90% purity by HPLC.
• Microbial contamination minimal or absent; suppliers provide COAs.
• Tested with LAL assays and sterility tests.

Identity and Quality Control

• Confirmed by high-resolution mass spectrometry (HRMS), ¹H and ¹³C NMR spectroscopy, and IR spectroscopy.
• Purity determined by HPLC.
• NHS ester activity verified by amine quantification assays.

Shelf Life and Storage

Applications

• Lipopeptide synthesis with hydrophilic spacers and reactive conjugation handles.
• Protein lipid modification for membrane targeting.
• Liposome formulation and surface modification.
• Bioconjugation reagent for linking molecules with lipid and PEG-like properties.

Key Characteristics

• Lipophilic stearic acid moiety enables membrane insertion.
• Hydrophilic PEG-like AEEA spacers improve solubility and reduce steric hindrance.
• Reactive NHS ester for primary amine conjugation.
• Acid-labile tert-butyl protecting groups allow controlled deprotection.
• Amphiphilic character combines hydrophilicity and lipophilicity.

Citation

• Search “stearic acid protein modification” or “lipid protein conjugation.”

• Search “PEGylation protein conjugation” or “AEEA spacer protein modification.”

• Use “NHS ester protein conjugation” or “OSu ester conjugation.”

• Look for “lipopeptide synthesis AEEA” and “PEGylated lipid modification.”

• Supplier datasheets and application notes.

• Chemical databases like Reaxys, SciFinder, PubChem.

• Google Scholar with targeted terms “tBuO-Ste-Glu(AEEA-AEEA-OSu)-OtBu,” “lipopeptide synthesis,” “PEGylated lipid conjugation,” “stearyl protein modification.”