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

tBuO-Ste-Glu(AEEA-AEEA-ONa)-OtBu is a synthetic glutamic acid derivative designed to impart both lipophilic and hydrophilic properties to biomolecules. The molecule has a glutamic acid core with one carboxyl group protected as a tert-butyl ester (OtBu) and the other functionalized on the side chain with two sequential AEEA units. The terminal carboxyl of the second AEEA is present as a sodium salt (ONa), providing a negative charge and enhanced water solubility. The alpha-amino group of glutamic acid is linked to a stearic acid moiety with a tert-butyl ester protection, serving as a lipid anchor. This compound is useful in forming self-assembling structures, modifying membrane interactions, or creating drug delivery systems with balanced amphiphilic character.

Appearance

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

Source

• Chemically synthesized, not naturally occurring

• Offered by specialized chemical suppliers focused on PEGylation, lipid modification, and bioconjugation reagents

Molecular Weight

• Estimated between 800–1100 g/mol, depending on exact chemical variants

Structure

• Stearic acid (tBuO-protected) attached via amide bond to glutamic acid α-amino group

• Glutamic acid core with one carboxyl protected as OtBu

• Two AEEA units linked via amide bonds sequentially on side chain carboxyl

• Terminal carboxyl of second AEEA ionized as sodium salt (ONa)

Biological Activity

• Typically biologically inert alone

• Stearic acid provides membrane affinity

• AEEA linkers increase hydrophilicity and reduce steric hindrance

• Sodium carboxylate adds negative charge, enhancing solubility

• Bioactivity depends on conjugated partners

Purity and Microbial Contamination

Shelf Life and Storage

• Expected shelf life 6–12 months, possibly shorter due to compound complexity

• Store at –20°C or below, tightly sealed under inert atmosphere (argon or nitrogen)

• Protect from moisture and light

Applications

• Lipid anchoring: attaching molecules to membranes or lipid bilayers

• PEGylation: imparting hydrophilicity and flexibility to biomolecules

• Drug delivery: enhancing water solubility, membrane permeability, and targeting

• Self-assembling systems: incorporation into micelles, liposomes, or nanostructures

• Surface modification: generating hydrophobic/hydrophilic coatings

Key Characteristics

• Lipophilic stearic acid chain for membrane interaction

• Hydrophilic PEG-like AEEA linker units improve solubility and reduce steric hindrance

• Negative charge from sodium carboxylate improves aqueous compatibility

• tBu protection allows controlled chemical synthesis steps

Citation 

• Search terms like “stearic acid protein modification,” “lipid conjugation protein,” “AEEA protein linker,” and “PEGylation drug delivery”

• Review lipopeptide synthesis and lipid-modified conjugate literature

• Consult technical data sheets from bioconjugation reagent suppliers

• Use chemical databases (Reaxys, SciFinder) to find related compounds and papers

• Search “liposome PEGylation” and “self-assembling lipid-polymers” for applications