Effects of high intensity focused ultrasound on lysozyme structure

Abstract:

Objective：To investigate the effect of high intensity focused ultrasound（HIFU） on the lysozyme molecular structure. Meth－ods：The lysozyme solution was exposed at HIFU with pulse frequency of 0.94 MHz，sound intensity of ３.25×104 W/cm2，pulse repetition period of 4 Hz and duty cycle of 10% for 10 s. The effect of HIFU on the lysozyme molecular structure was studied using CD spectra，fluorescence spectrum，1H nuclear magnetic resonance（1H-NMR） and sodium dodecyl sulfate-polyacrylamide gel（SDS-PAGE） method. Results：The Result showed that after HIFU treatment，there was no obvious change in CD spectrum，indicating that HIFU might cause little effect on lysozyme lower structure. Whereas a weaken fluorescence intensity appeared indicating lysozyme conformation change. Data of SDS-PAGE showed obvious degradation of lysozyme branches. 1H-NMR analysis demonstrated that tryptophan（Trp） residue of lysozyme displayed chemical shift after treatment. Conclusion：The conformation structure of lysozyme could be changed by HIFU.