Surfactant copolymers prevent aggregation of heat denatured lysozyme

Raphael C. Lee, Florin Despa, L. Guo, Pravin Betala, Anne Kuo, P. Thiyagarajan

Research output: Contribution to journalArticlepeer-review

31 Scopus citations


We investigated the ability of certain triblock copolymer surfactant poloxamers of the form polyethylene oxide-polypropylene oxide-polyethylene oxide (PEO-PPO-PEO), to prevent formation of stable aggregates of heat denatured hen egg lysozyme. Differential scanning calorimetry (DSC) and synchrotron small angle x-ray scattering (SAXS) experiments were performed to study the thermodynamics and solution structures of lysozyme at temperatures between 20 and 90°C in the presence and absence of poloxamers with various molecular weights (8.4-14.3 kDa), but similar hydrophile/hydrophobe (PEO:PPO) ratio of 80%. Poloxmer 188 was found to be very effective in preventing aggregation of heat denatured lysozyme and those functioned as a synthetic surfactant, thus enabling them to refold when the conditions become optimal. For comparison, we measured the ability of 8 kDa polyethylene glycol (PEG) to prevent lysozyme aggregation under same conditions. The results of these studies suggest that poloxamers are more efficient than PEG in preventing aggregation of heat denaturated lysozyme, To achieve equivalence, more than an order of magnitude higher concentration of PEG concentration was needed. Apparently, the presence of a hydrophobic segment in the poloxamers increases their ability to target the hydrophobic region of the unfolded proteins and protect them from self association. Given their biocompatibility and the low concentrations at which they effectively facilitate refolding of denatured proteins, they may be useful in the treatment of burns and other conditions resulting in the denaturation of proteins.

Original languageEnglish
Pages (from-to)1190-1200
Number of pages11
JournalAnnals of Biomedical Engineering
Issue number7
StatePublished - Jul 2006

Bibliographical note

Funding Information:
The research presented here has been supported by the National Institutes of Health, grants R01 GM61101 and R01 GM64757. Work benefited by the use of APS and IPNS funded by DOE-BES under contract #W-31-109-ENG-38 and the BioCAT beam line at the APS funded by NCRR/NIH.


  • DSC
  • Heat denatured proteins
  • Poloxamer
  • Protein refolding
  • SAXS
  • Surfactants

ASJC Scopus subject areas

  • Biomedical Engineering


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