Immobilized beta-cyclodextrin polymer coupled to agarose gel properly refolding recombinant Staphylococcus aureus elongation factor-G in combination with detergent micelle

Protein Expr Purif. 2006 Jan;45(1):72-9. doi: 10.1016/j.pep.2005.05.006. Epub 2005 Jun 14.

Abstract

A novel artificial chaperone system using a combination of interactions between the unfolded protein, a detergent and a chromatographic column packed with immobilized beta-cyclodextrin (beta-CD) polymer coupled to an agarose gel, was introduced to refold recombinant Staphylococcus aureus elongation factor-G (EF-G). Pre-mixing of 10% Triton X-100 and unfolded EF-G at 24 mg/ml followed by a 20-fold dilution into refolding buffer led to successful capturing of EF-G by Triton X-100 resulting in formation of a detergent-protein complex at 1.2mg/ml of final protein concentration. The complex was subsequently applied to the immobilized beta-CD polymer column resulting in correct refolding of EF-G at a concentration of 530 microg/ml with 99% mass recovery. Detergent concentrations above critical micelle concentration were required for efficient capturing of EF-G at high protein concentration. Other detergents with hydrophile-lipophile-Balance values similar to that of Triton X-100 (Triton N-101, Noindet P40 (NP40), and Berol 185) also produced similar result. Soluble polymerized beta-CD was more efficient than the monomer to remove the detergent from the protein complex in a batch system. Immobilized beta-CD polymer column further improved the capability of detergent removal and was able to prevent aggregation that occurred with the addition of soluble beta-CD polymer at high protein concentration in the batch system. The mechanism for this system-assisted refolding was tentatively interpreted: the released protein could correctly refold in an enclosed hydrophilic environment provided by the integration of matrix and beta-CD polymer, and thus avoided aggregation during detergent removal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electrophoresis, Agar Gel / methods
  • Micelles
  • Octoxynol / chemistry
  • Peptide Elongation Factor G / chemistry*
  • Polymers / chemical synthesis
  • Polymers / chemistry*
  • Polymers / isolation & purification
  • Protein Folding*
  • Recombinant Proteins / chemistry
  • Sepharose / chemistry*
  • Staphylococcus aureus / chemistry*
  • Time Factors
  • beta-Cyclodextrins / chemical synthesis
  • beta-Cyclodextrins / chemistry*
  • beta-Cyclodextrins / isolation & purification

Substances

  • Micelles
  • Peptide Elongation Factor G
  • Polymers
  • Recombinant Proteins
  • beta-Cyclodextrins
  • Octoxynol
  • Sepharose