skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Conjugation of Amphiphilic Proteins to Hydrophobic Ligands in Organic Solvent

Journal Article · · Bioconjugate Chemistry

Protein–ligand conjugations are usually carried out in aqueous media in order to mimic the environment within which the conjugates will be used. Here, we focus on the conjugation of amphiphilic variants of elastin-like polypeptide (ELP), short elastin (sEL), to poorly water-soluble compounds like OPPVs (p-phenylenevinylene oligomers), triarylamines, and polypyridine-metal complexes. These conjugations are problematic when carried out in aqueous phase because hydrophobic ligands tend to avoid exposure to water, which in turn causes the ligand to self-aggregate and/or interact noncovalently with hydrophobic regions of the amphiphile. Ultimately, this behavior leads to low conjugation efficiency and contamination with strong noncovalent “conjugates”. After exploring the solubility of sEL in various organic solvents, we have established an efficient conjugation methodology for obtaining covalent conjugates virtually free of contaminating noncovalent complexes. When conjugating carboxylated ligands to the amphiphile amines, we demonstrate that even when only one amine (the N-terminus) is present, its derivatization is 98% efficient. When conjugating amine moieties to the amphiphile carboxyls (a problematic configuration), protein multimerization is avoided, 98–100% of the protein is conjugated, and the unreacted ligand is recovered in pure form. Our syntheses occur in “one pot”, and our purification procedure is a simple workup utilizing a combination of water and organic solvent extractions. This conjugation methodology might provide a solution to problems arising from solubility mismatch of protein and ligand, and it is likely to be widely applied for modification of recombinant amphiphiles used for drug delivery (PEG-antibodies, polymer-enzymes, food proteins), cell adhesion (collagen, hydrophobins), synthesis of nanostructures (peptides), and engineering of biocompatible optoelectronics (biological polymers), to cite a few.

Research Organization:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division; USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
AC52-06NA25396
OSTI ID:
1461400
Report Number(s):
LA-UR-18-21399
Journal Information:
Bioconjugate Chemistry, Vol. 29, Issue 8; ISSN 1043-1802
Publisher:
American Chemical SocietyCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

Similar Records

Protein Bodies in Leaves Exchange Contents through the Endoplasmic Reticulum
Journal Article · Mon May 23 00:00:00 EDT 2016 · Frontiers in Plant Science · OSTI ID:1461400

Synthesis and Characterization of Smart Block Copolymers for Biomineralization and Biomedical Applications
Thesis/Dissertation · Tue Jan 01 00:00:00 EST 2008 · OSTI ID:1461400

Supramolecular Assembly of Peptide Amphiphiles
Journal Article · Wed Sep 06 00:00:00 EDT 2017 · Accounts of Chemical Research · OSTI ID:1461400