Reinvestigation of the oxidative folding pathways of hen egg white lysozyme: switching of the major pathways by temperature control

Int J Mol Sci. 2013 Jun 26;14(7):13194-212. doi: 10.3390/ijms140713194.


It has been well established that in the oxidative folding of hen egg white lysozyme (HEL), which has four SS linkages in the native state (N), three des intermediates, i.e., des[76-94], des[64-80], and des [6-127], are populated at 20 °C and N is dominantly formed by the oxidation of des[64-80] and des[6-127]. To elucidate the temperature effects, the oxidative folding pathways of HEL were reinvestigated at 5-45 °C in the presence of 2 M urea at pH 8.0 by using a selenoxide reagent, DHSox. When reduced HEL was reacted with 1-4 equivalents of DHSox, 1S, 2S, 3S, and 4S intermediate ensembles with 1-4 SS linkages, respectively, were produced within 1 min. After the oxidation, 3S was slowly converted to the des intermediates with formation of the native structures through SS rearrangement. At 5 °C, des[76-94] was populated in the largest amount, but the oxidation to N was slower than that of des[64-80] and des[6-127]. At 35 °C, on the other hand, des[64-80] and des[6-127] were no longer stable, and only des[76-94] was populated. The results suggested that the major folding pathways of HEL can be switched from one to the other by temperature control.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chickens / metabolism
  • Disulfides / chemistry
  • Egg White
  • Female
  • Kinetics
  • Muramidase* / chemistry
  • Oxidation-Reduction
  • Protein Denaturation
  • Protein Folding
  • Ribonuclease, Pancreatic
  • Temperature*


  • Disulfides
  • Ribonuclease, Pancreatic
  • Muramidase