C20-OtBu-Glu(OtBu)-AEEA-AEEA-OSU

C20-OtBu-Glu(OtBu)-AEEA-AEEA-OSU is a synthetic glutamic acid derivative designed for advanced peptide or protein modification. It features a glutamic acid core with both carboxyl groups protected as tert-butyl esters (OtBu). The alpha-amino group is acylated with a C20 (eicosanyl) fatty acid chain conferring lipophilicity. Two AEEA units form a hydrophilic, PEG-like spacer linked to the side chain carboxyl group, terminating in an N-hydroxysuccinimide (OSU) ester. The OSU ester enables conjugation to primary amines of peptides, proteins, or other molecules. This compound introduces a lipid anchor and flexible hydrophilic spacer, enhancing membrane affinity, water solubility, and bioavailability. The protecting groups facilitate selective chemical synthesis.

Appearance

• White to off-white solid, potentially waxy due to the long alkyl chain

Source

• Chemically synthesized, not naturally occurring

• Available through specialized suppliers focusing on modified amino acids, PEGylation, and bioconjugation reagents

Molecular Weight

• Estimated between 800–1000 g/mol (exact value depends on component variants and protecting groups)

Structure

• C20 eicosanyl fatty acid attached to alpha-amino group of glutamic acid via amide bond

• Glutamic acid core with tert-butyl ester protections on carboxyl groups

• Two AEEA linkers attached sequentially on side chain carboxyl group via amide bonds

• Terminal OSU ester at C-terminus of second AEEA unit

Biological Activity

• Generally biologically inert as an isolated molecule

• Activity depends on what it is conjugated to

• Provides membrane anchoring through the lipophilic C20 chain

• Improves solubility and reduces steric hindrance via AEEA spacers

• OSU ester facilitates covalent conjugation to primary amines

Purity and Microbial Contamination

Shelf Life and Storage

• Likely shorter than simpler reagents due to OSU ester hydrolysis sensitivity; typically 6–12 months

• Store at -20°C or below, in dry, inert atmosphere (argon or nitrogen)

• Protect from moisture, light, and heat

Applications

• Protein and peptide modification introducing lipid anchors and hydrophilic spacers

• Enhancing membrane affinity and bioavailability of conjugated molecules

• PEGylation and bioconjugation reagent

• Drug delivery: creating membrane-targeted, hydrophilic drug conjugates

• General reagent for conjugating molecules to primary amines

Key Characteristics

• Lipophilic: C20 eicosanyl chain provides strong membrane association

• Hydrophilic: AEEA spacers confer PEG-like solubility and reduce steric effects

• Reactive: OSU ester efficiently couples with primary amines

• tBu Protection: tert-butyl esters protect glutamic acid carboxyl groups during synthesis

Citation 

• Search “C20 fatty acid protein modification” or “lipid modification protein conjugation” for fatty acid-based conjugates

• Explore “PEGylation protein conjugation” or “AEEA protein modification” for PEG-like linker studies

• Look up “OSU ester protein conjugation” or “NHS ester protein modification” for reactive ester chemistries

• Review lipopeptide synthesis literature for use of lipid anchors

• Search “PEGylation for drug delivery” for enhanced drug bioavailability

• Utilize chemical databases (Reaxys, SciFinder) for related compounds

• Check supplier catalogs for application notes and data sheets

• Use Google Scholar with keywords like “C20 protein modification” or “AEEA OSU conjugation” to find articles