Study On The Unfolding Pathway And Renaturation Of The Structure Pf Glucose Oxidase In Micelle

Surfactants are one of the most frequently used reagents in the study of purification, renaturation and activity of functional membrane proteins and inclusion body proteins in organism.The secondary and tertiary structure of proteins can be changed in the process of interaction of surfactants and proteins.In order to discover how surfactants unfold proteins, the interaction of Glucose Oxidase (GOD) with three anionic surfactants sodium dodecyl sulfate (SDS), sodium octyl and sulfate (SOS), sodium octanoate (SO) and one cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB) in the (pH3.920mM) NaAc-HAc buffer solutions and (pH5.920mM) Na2HPO4-NaH2PO4buffer solutions has been investigated by ultraviolet absorption spectrometry, intrinsic fluorescence spectrometry, circular dichroism, isothermal titration calorimetry.The experiment results show:FAD is the important composition for the activity of GOD, the losing of FAD can lead to the reducing of activity of GOD. The electrostatic interaction is the important influence factor in the interaction of GOD with anionic surfactants, however, the electrostatic interaction is not the important influence factor in the interaction of GOD with cationic surfactants. The nonpolar hydrocarbon chain tail of anionic surfactants is the important influence factor in proteins unfolding and structure renaturation. The longer the hydrocarbon chain of anionic surfactants is, the greater the force between anionic surfactants and GOD will be. Whether anionic surfactants or cationic surfactants, the polar head of surfactants is the important influence factor in proteins unfolding and structure renaturation. The force between sulfo group-SO4-and GOD is greater than carboxyl group. It is very important to clarify the structure and function of proteins as well as purify and stabilize economically valuable proteins.