Surfactant-induced refolding of lysozyme.
The surfactant-lysozyme interaction was investigated by circular dichroism, fluorescence, UV, dynamic light scattering, surface tension, turbidity measurements and lysozyme activity assay. A new way of refolding of lysozyme was found. It was shown that the lysozyme unfolded by anionic surfactants could be renatured by adding cationic surfactants. That is, lysozyme formed precipitate with anionic surfactants, the precipitates could be dissolved by adding a cationic surfactant solution, and then the lysozyme was refolded to its native state spontaneously. Different couples of anionic surfactants and cationic surfactants including C10SO3/C10NE, C12SO3/C10NE, C10SO3/C12NE, C10SO3/C12NB, C10SO4/C10NE and C12SO4/C10NE (C(n)SO3, C(n)SO4, C(n)NE and C(n)NB represent sodium alkyl sulfonate/sulfate, alkyl triethyl/butyl ammonium bromide respectively) were investigated, all of them gave similar results. The results were explained in terms of the differences between the interaction of anionic-cationic surfactants and that of surfactant-lysozyme. It was thought that the formation of mixed micelles of anionic-cationic surfactants is a more favorable process than that of lysozyme-surfactant complexes, which induces the dissociation of lysozyme-surfactant complexes when cationic surfactants were added.
Lu
Run-Chao
RC
College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.
Xiao
Jin-Xin
JX
Cao
Ao-Neng
AN
Lai
Lu-Hua
LH
Zhu
Bu-Yao
BY
Zhao
Guo-Xi
GX
D002942:Circular Dichroism; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism*; D017510:Protein Folding; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*
D013501:Surface-Active Agents; D009113:Muramidase