Zhang Qiuting, Tu Zongcai, Wang Hui, Huang Xiaoqin, Sha Xiaomei, Xiao Hui
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi, 330047, China.
Anal Bioanal Chem. 2014 Nov;406(28):7243-51. doi: 10.1007/s00216-014-8136-6. Epub 2014 Sep 16.
The structural changes of bovine serum albumin (BSA) under high-intensity ultrasonication were investigated by fluorescence spectroscopy and mass spectrometry. Evidence for the ultrasonication-induced conformational changes of BSA was provided by the intensity changes and maximum-wavelength shift in fluorescence spectrometry. Matrix-assisted laser desorption-ionization time-of-flight mass spectroscopy (MALDI-TOF MS) revealed the increased intensity of the peak at the charge state +5 and a newly emerged peak at charge state +6, indicating that the protein became unfolded after ultrasonication. Prevalent unfolding of BSA after ultrasonication was revealed by hydrogen-deuterium exchange coupled with mass spectrometry (HDX-MS). Increased intensity and duration of ultrasonication further promoted the unfolding of the protein. The unfolding induced by ultrasonication goes through an intermediate state similar to that induced by a low concentration of denaturant.
通过荧光光谱法和质谱法研究了高强度超声作用下牛血清白蛋白（BSA）的结构变化。荧光光谱法中的强度变化和最大波长偏移为超声诱导的BSA构象变化提供了证据。基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）显示，电荷状态为+5时峰强度增加，电荷状态为+6时出现新峰，表明超声处理后蛋白质发生了去折叠。氢-氘交换结合质谱（HDX-MS）揭示了超声处理后BSA普遍发生去折叠。超声强度和持续时间的增加进一步促进了蛋白质的去折叠。超声诱导的去折叠经历了一个类似于低浓度变性剂诱导的中间状态。
