XeCl准分子紫外激光辐照生物大分子BSA(V)对其蛋白质结构的影响

XeCl(308 nm)准分子紫外激光(单脉冲输出能量25 mJ,33.3 mJ~34.4 mJ,脉冲频率每秒两次,光斑15 mm×7 mm或4.5 mm×0.5 mm,透镜焦距300 mm),辐照小牛血清白蛋白[bovine serum albumin fraction V,BSA(V)]固体或溶液样品的时间分别为15 s、30 s、45 s或60 s;样品距激光光源的距离分别为:150 mm、250mm、290 mm、340 mm。改变激光参量辐照BSA(V)样品和其对照,用光谱法测试其FT-IR(IR)、Vis-UV(UV)、FR光谱,并比较分析。受辐照后的BSA(V)与主链构象相关的酰胺平面的特征FT-IR谱线,特别是与蛋白质二级结构敏感的酰胺面Ⅰ,1 652 cm-1;与α-螺旋结构相关的FT-IR 1 140 cm-1~500 cm-1;及与蛋白质侧链氨基酸残基Tyr、Phe、Trp相关的特征峰UV277.6 nm、UV216 nm和FR 340 nm、FR 680 nm的峰强度(T%或OD%或Q%)和它们的峰位(cm-1或nm)均受激光辐照的影响,其影响程度与使用的XeCl激光参量的改变有一定的敏感性和相关性。实验结果与讨论对认识激光生物学效应的分子机理、探索建立激光-生物学效应的关系参数,以便进一步发现新的有效的激光生物学效应,发现和认识潜在(后继)的正、负面的激光生物学效应,进而加以调控有一定的理论与实用参考价值。

The Effect of XeCl Excimer Laser Radiation on Biomacromolecule Structure of BSA (V)

The biomacromolecule of bovine serum albumin fraction V[BSA(V)]powder or it's solution was radiated seperately by XeCl excimer laser(308 nm)in the condition of export out power 25 mJ/per pulse or 33.3 mJ/per pulser~34.4 mJ/per pulse,pulse frequency 2 times/s.The radiation samples were set on different distance:150 mm,250 mm,290 mm,or 340 mm.Far from laser source,and went through different radiation time: 15 s,30 s,45 s or 60 s.The radiated samples of BSA(V) and their control were measured by FT-IR,Vis-UV,and FR,then they were observed and analyzed,and compared with the above two data. The results showed that: relative BSA(V) sample protein structure(confomation)spectra,which is either protein main-chain FT-IR spectra lines(peaks),special for the amide plate-I,1 652 cm-1,or the protein side-chain amino acid residuce groups,Tyr,Phe,Trp,spectra lines 277.6 nm,216 nm(UV),340 nm,680 nm(FR),their peak intensity and the peak position all appeared great changers,and the changing degree of the radiating samples spectra is corresponding to the changing of the radiation parameters on the samples.It shows that laser is an important environmental factor to cause the structure swich(comformation change) of protein in the microconic structure area,and make bio-signal transfer.