title: Interaction of cellulase with sodium dodecyl sulfate at critical micelle concentration level.
abstract: The interactions between Trichoderma reesei cellulase and an anionic surfactant, sodium dodecyl sulfate (SDS), at critical micelle concentration level have been investigated using isothermal titration calorimetry, fluorescence spectroscopy, and circular dichroism. SDS micelles have dual interactions with cellulase: electrostatic at first and then hydrophobic interactions. When the concentration of SDS is smaller than 45.0mM, SDS micelles cause a partial loss in the hydrolytic activity together with a steep decrease in the alpha-helical content of cellulase. With further increasing the concentration of SDS, however, a re-formation of the alpha-helical structure and a partial recovery of the hydrolytic activity of cellulase induced by SDS micelles are observed. Taken together, these results indicate that SDS micelles exert dual effects on cellulase through binding as both a denaturant and a recovery reagent.
authors.affiliation: State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Xiang
authors.forename: Jun-Bao
authors.initials: JB
authors.lastname: Fan
authors.forename: Nan
authors.initials: N
authors.lastname: Chen
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Yi
authors.initials: Y
authors.lastname: Liang
mesh_terms: D002151:Calorimetry; D002480:Cellulase / Q000737:chemistry*; D002942:Circular Dichroism; D008823:Micelles; D017433:Protein Structure, Secondary; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D017186:Titrimetry; D014242:Trichoderma / Q000201:enzymology
chemical_list: D008823:Micelles; D012967:Sodium Dodecyl Sulfate; D002480:Cellulase